Edexcel GCSE Chemistry Paper 2

#1. What is the chemical symbol for helium?

enter answer here...

#2. Lead has 4 stable isotopes. ²⁰⁴Pb (abundance - 1.4%), ²⁰⁵Pb (abundance - 24.1%), ²⁰⁷Pb (abundance - 22.1%) and ²⁰⁸Pb (abundance - 52.4%). Calculate the Aᵣ of lead. Answer to 2 decimal places.

enter answer here...

#3. In the modern periodic table, elements are arranged in increasing order of which number?

Relative atomic mass

Relative formula mass

Atomic number

#4. What is the electronic configuration of magnesium?

2,2,8

2,8,8

2,8,2

2,8,3

#5. Calculate the empirical formula of a compound that contains 69.94g of Fe (Aᵣ - 55.85) and 30.06g of O (Aᵣ - 12.00).

Fe₃O

FeO₂

Fe₂O₃

Fe₂O

#6. Temperature affects the rate of reaction. Which of the following is the correct description of what happens when temperature changes?

As temperature increases, rate of reaction decreases

As temperature increases, rate of reaction increases

Rate of reaction is highest at very high and very low temperatures

#7. What is the chemical symbol for lithium?

enter answer here...

#8. What is the formula for potassium oxide? ? you might need a periodic table to answer this question

enter answer here...

#9. Which of the following statements is accurate about group number?

Group number tells us the number of neutrons in the nucleus of an element

Group number tells us the number of electrons in total

Group number tells us the number of protons in the nucleus of an element

Group number tells us the number of electrons in the outermost shell

#10. In the modern periodic table, what are rows and columns called?

Rows are periods and columns are groups

Rows are called atomic lines and columns are groups

Columns are periods and rows are groups

Columns are groups and rows are called rows

#11. What is the charge of a neutron?

+1

0

-1

#12. What is the formula for the polyatomic ion nitrate?

SO₄²⁻

NO₃⁻

SO₃²⁻

NH₄⁺

CO₃²⁻

OH⁻

#13. In which of the following are chemical properties similar in the periodic table?

Periods

Groups

Arms

Legs

#14. Greenhouse effect 1) Fill in the blanks: Energy from the sun in the form of ........ hits the Earth's surface and ....... are emitted back towards the atmosphere.

Visible/infrared waves, infrared waves

Sound waves, ocean waves

Gravitational waves, ultraviolet waves

#15. Greenhouse effect 2) Fill in the blanks: Greenhouse gases such as ........... , ............. and ........... absorb infrared radiation from the Earth and re-emit it back to the Earth's surface, causing warming.

Carbon dioxide, water vapour and nitrogen

Carbon dioxide, oxygen and water vapour

Carbon dioxide, methane and water vapour

#16. Which of the following is the chemical test for oxygen?

Oxygen is bubbled through limewater and it turns cloudy when oxygen is present

An audible squeaky pop is heard when a lit splint is exposed to a test tube full of oxygen

A glowing splint is relit in a test tube filled with oxygen

#17. Dimitri Mendeleev developed the first periodic table. How did he arrange the elements in the table?

In order of increasing atomic mass (atomic weight)

In order of increasing reactivity

In order of increasing atomic number (proton number)

In order of decreasing reactivity

#18. What is the charge of a proton?

+1

-1

0

#19. Which of these reasons explains why temperature affects rate of reaction?

Reactant particles at higher temperatures move more quickly, collide more often and with enough energy to react

Reactant particles are unaffected by temperature, but the bonds at higher temperatures become weaker leading to an increased rate of reaction

Reactant particles at lower temperatures are struck by rapidly moving electrons, causing the reaction to happen faster

#20. Increasing the concentration of solutions increases the rate of reaction, why is this the case?

More collisions take place because there are more particles in the same volume

When solutions are more concentrated, the intermolecular forces become weaker and bonds are more easily broken

When solutions are dilute, there are more particles in the same volume

#21. How many atoms of potassium (group 1) are needed to bond ionically with oxygen (group 6)?

1

3

2

#22. Which of the following examples matches the composition of Earth's early atmosphere?

Mainly water vapour, some oxygen, little or no carbon dioxide and small amounts of other gases

Mainly oxygen, some water vapour, little or no carbon dioxide and small amounts of other gases

Mainly carbon dioxide, some water vapour, little or no oxygen and small amounts of other gases

#23. What is the formula for the polyatomic ion hydroxide?

SO₄²⁻

SO₃²⁻

NH₄⁺

NO₃⁻

CO₃²⁻

OH⁻

#24. What are negative ions called?

enter answer here...

#25. What is the formula for the polyatomic ion sulfate?

NH₄⁺

CO₃²⁻

SO₃²⁻

SO₄²⁻

NO₃⁻

OH⁻

#26. Why did the amount of oxygen in the atmosphere increase over time?

Oxygen present in the Earth's mantle, seeped out over time and escaped via deep ocean ridges

Plants and other organisms began to perform photosynthesis, producing oxygen gas

Oxygen was released during the Great Oxidation Period from extensive volcanic activity

#27. What are positive ions called?

anions

cations

#28. On the early Earth, there was a lot of volcanic activity as the planet was cooling down. How can we link this to the formation of the atmosphere?

Assume that volcanic activity is not relevant to the atmosphere and look for other sources of gases

Measure the gases released by volcanoes and compare them to the composition of the atmosphere over time

#29. What is the current composition of the Earth's atmosphere?

78% carbon dioxide, 21% oxygen, 0.9% argon, and 0.1% other gases

78% nitrogen, 21% oxygen, 0.9% argon, and 0.1% other gases

78% oxygen, 21% nitrogen, 0.9% argon, and 0.1% other gases

#30. Hydrogen has two stable isotopes, ¹H (abundance - 99.972%) and ²H (abundance - 0.001%). Calculate the Aᵣ of hydrogen. Answer to 3 decimal places.

enter answer here...

#31. Calculate the relative formula mass of copper oxide (CuO) to 2 decimal places. Copper Aᵣ = 63.5, Oxygen Aᵣ = 16.

enter answer here...

#32. Which type of reaction transfers energy to the surroundings?

Exothermic

Endothermic

Mesothermic

#33. True or false - volcanism removes carbon from the atmosphere

true

false

#34. Which type of reaction takes in energy, making the surroundings cooler?

Endothermic

Ectothermic

Exothermic

#35. Decomposers break down dead animal and plant material - what happens to the carbon inside the dead organisms?

all of the carbon becomes part of the decomposers

all of the carbon is released during respiration

part of the carbon is released during respiration and part is stored in the composers cells

#36. When fossil fuels are burned they release carbon into the atmosphere - which of the following are fossil fuels?

peat

nuclear fuels

wind

#37. Determine the empirical formula of glucose - C₆H₁₂O₆.

CHO₂

CH₂O

C₂OH

C₂H₂O

#38. True or false - carbon dioxide is removed from the atmosphere as it dissolves in the oceans?

false

true

#39. What is the relative mass of an electron?

2

0 or 1/1840

1

#40. How did the oceans form?

Liquid water gradually seeped directly out of the Earths crust, for thousands of years

Water vapour in the atmosphere condensed as the Earth cooled, forming the oceans

Liquid water spontaneously formed when the ammonia and and methane in the atmosphere interacted chemically

#41. Where are metals and non-metals found on the periodic table?

Non-metals on the right, metals of the left

Non-metals at the bottom, metals at the top

Non-metals at the top, metals at the bottom

Non-metals on the left, metals of the right

#42. True or false. All atoms of the same element have the same atomic number.

False

True

#43. What is the name of the force that holds together ions in ionic compounds?

weak nuclear force

electrostatic force

gravity

strong nuclear force

#44. What is the electronic configuration of a nitrogen atom? ? you might need a periodic table to answer this question

2,8,5

2,5

2,7

#45. Which evidence provides information about carbon dioxide concentration and global temperatures?

Using the oldest continuous temperature measurements from humans and using computers to predict long term trends with this data

Ice cores which trap atmospheric gases when snow falls producing layers over time

#46. Which three particles are atoms composed of?

enter answer here...

#47. Which of the following statements is accurate about period number?

Period number tells us the number of occupied electron shells

Period number tells us the number of protons plus neutrons

Period number tells us the number of empty electron shells

Period number tells us the number of protons in the nucleus

#48. Determine the molecular formula of glucose which has an empirical formula of CH₂O. The Mᵣ for glucose is 180. Carbon Aᵣ - 12, Hydrogen Aᵣ - 1, Oxygen Aᵣ - 16.

C₆H₁₂O₆

C₂H₆O₂

CH₂O

#49. What is the formula for the polyatomic ion sulfite?

OH⁻

NH₄⁺

SO₄²⁻

NO₃⁻

CO₃²⁻

SO₃²⁻

#50. Energy is transferred between the environment and reactants during a chemical reaction. What form is this energy usually in?

Electrical

Chemical

Thermal

#51. Reaction profiles are used to show the energy transfers during reactions. Which type of reaction is shown in this reaction profile?

Ectothermic

Mesothermic

Endothermic

Exothermic

#52. What evidence supports the notion that human activities are contributing to climate change?

Correlation between increases in atmospheric temperatures and historic releases of greenhouse gases, due to combustion of fossil fuels

Gradual climate warming has occurred since the evolution of our species

#53. When there are more frequent collisions between particles, what will happen to the rate of reaction?

It will stay the same

It will decrease

It will increase

#54. Which of the following descriptions matches the Aᵣ of an element?

The sum of the relative atomic masses of all of the atoms or ions in its formula

The mean mass of an atom compared with carbon-12

The simplest whole number ratio of atoms

#55. Why may our attempts to mitigate the effects of climate change cause further damage to the environment?

Unexpected consequences often follow when we interrupt complex systems that do not fully understand e.g. the atmosphere

Animals and plants will resist the efforts we take to help them causing distress and loss of ecological productivity

Vulnerable ecosystems may be disrupted in our attempts to improve conditions for humans

#56. Chlorine has two stable isotopes, ³⁵Cl (75.77%) and ³⁷Cl (24.23%). Calculate the Aᵣ of chlorine to 2 decimal places.

enter answer here...

#57. True or false - plants remove carbon from the atmosphere during photosynthesis

true

false

#58. Why do historical measurements by humans of global temperature have some uncertainty?

Select all that apply:

Early scientists were in competition to record the highest temperatures

The longest continuous record of temperature is only available in one place

Instruments to measure temperature were not very accurate in the past and have gained more resolution over time

#59. Atomic number represents the number of protons in the nucleus of an atom. This means that elements further down the table have:

More neutrons

Less electrons

More protons

Less protons

#60. How could we accurately monitor the rate of a reaction? ? Three answers

Select all that apply:

By measuring the concentration of reactants and products throughout a reaction

By measuring the changes in volume of reactants and products

By measuring the changes in mass of reactants and products

By measuring the temperature throughout a reaction

#61. What is the formula for the polyatomic ion ammonium?

CO₃²⁻

SO₄²⁻

NH₄⁺

OH⁻

NO₃⁻

SO₃²⁻

#62. Why is there a minimum energy required for reactions to occur?

High energies cause spontaneous rearrangement of particles without impacts between them

High collision energies are more likely to break chemical bonds

#63. Determine the empirical formula for Cyclopentane - C₅H₁₀?

C₂H₂

CH₂

2CH

CH₄

#64. What is the symbol for relative atomic mass?

Aᵣ

AMᵣ

Mᵣ

Gᵣ

#65. Which type of reaction is photosynthesis?

Endothermic

Ectothermic

Exothermic

#66. What are ions?

atoms which have different numbers of neutrons

atoms which have different numbers of protons

atoms which have gained or lost electrons

#67. Which of these is a fast reaction?

Photosynthesis

Rusting

Explosions

#68. What is the mass number of an element?

the number of protons plus neutrons

the total number of subatomic particles in an atom

#69. What is the charge of an electron?

+1

0

-1

#70. What is the electronic configuration of boron?

3,2

2,7

2,3

2,4

#71. Isotopes of atoms have different numbers of which particles?

Neutrons

Protons

#72. Determine the empirical formula for Cyanuric triazide - C₃N₁₂.

CN

CN₄

C₄N₄

C₂N₄

#73. What is the formula for the polyatomic ion carbonate?

OH⁻

SO₃²⁻

NO₃⁻

SO₄²⁻

CO₃²⁻

NH₄⁺

#74. Which of the following is the correct maximum number of electrons in the first three shells?

3,7,7

4,8,8

2,8,8

2,6,8

#75. What is the symbol for relative formula mass (also known as relative molecular mass)?

Hᵣ

MAᵣ

Mᵣ

Aᵣ

#76. What do group 2 atoms do when they bond with group 6 atoms?

gain one proton

lose two electrons

lose two neutrons

gain two electrons

#77. True or false - Precipitation reactions can be either exothermic or endothermic.

False

True

#78. Mendeleev did not know about isotopes, this caused his periodic table to have pair reversals where elements with a higher atomic weight were placed before elements with a lower atomic weight. Which subatomic particles are found in different numbers in isotopes?

Electrons

Protons

Neutrons

#79. Iron is turned into iron oxide when exposed to the air. This is a process also known as rusting. Is the rate of reaction fast or slow in rusting?

Slow

Fast

#80. What is the evidence supporting the idea that there was very little oxygen in the atmosphere in Earth's early atmosphere?

Select all that apply:

No iron oxide bands in layers of rock are present in deeper (older) layers

The gravitational field strength of the Earth is not strong enough to hold oxygen in the atmosphere

Oxygen is not produced by volcanoes

#81. Surface area to volume ratio affects rate of reaction. Why is that the case?

With higher surface area to volume ratio, there is more surface where collisions can take place

With lower surface area to volume ratio, objects are much hotter and travel faster

With higher surface area to volume ratio, the overall temperature of reactants is lower, this leads to increased collision impact when struck

#82. Which of the following was a feature of Mendeleev's periodic table?

Select all that apply:

He swapped the positions of some elements based on their chemical properties

Elements in his table were arranged in rows with similar properties

Elements in his table were arranged in columns (groups) with similar properties

He left gaps in his table where he predicted elements would fit when discovered in the future

He strictly followed the order of increasing atomic weight, ignoring chemical properties of elements

#83. How do sodium and chlorine atoms bond? ? you might need a periodic table to answer this question

metallically

covalently

ionically

#84. Most ionic bonds are formed between which groups?

metals and non-metals

metals and metals

non-metals and non-metals

#85. Why did the concentration of carbon dioxide in the atmosphere decrease after the oceans formed?

Carbon dioxide was split by photolysis, producing pure carbon which rained down as a solid.

Carbon dioxide escaped the atmosphere as the Earth's spin increased in speed, causing an increase the centrifugal force

Carbon dioxide dissolved into the oceans and sea organisms used carbon in their shells as calcium carbonate

#86. Calculate the relative formula mass of carbon monoxide (CO) to 2 decimal places. Carbon Aᵣ = 12, Oxygen Aᵣ = 16.

enter answer here...

#87. Which type of reaction is aerobic respiration?

Exothermic

Ectothermic

Mesothermic

Endothermic

#88. What is the relative mass of a neutron?

1/1840

1

2

#89. Reaction profiles are used to show the energy transfers during reactions. Which type of reaction is shown in this reaction profile?

Exothermic

Ectothermic

Mesothermic

Endothermic

#90. What is the formula for the compound calcium nitrate which is made of calcium and nitrate ions (NO₃⁻)?

CaNO₂

Ca(NO₃)₂

Ca(NO₂)₂

#91. Will endothermic reactions continue if there is no energy input?

No, even if there are still reactants

Yes, until reactants run out

#92. Neutralisation reactions which occur between an acid and a base are always:

Exothermic

Endothermic

#93. Does increasing the pressure of gases increase the rate of reaction?

No

Yes

Sometimes

#94. In which type of reaction would the temperature of a solution increase?

Exothermic

Endothermic

Mesothermic

Ectothermic

#95. Which human activities cause increases in the greenhouse gases - carbon dioxide and methane?

Select all that apply:

Burning fossil fuels

Planting trees

Livestock farming

#96. Which of the following are properties of ionic compounds?

usually insoluble

conduct electricity as solids

usually soluble

conduct electricity when molten or dissolved

high melting and boiling points

low melting and boiling points

#97. Which of the following descriptions matches the Mᵣ of a compound?

The mean mass of an atom compared with carbon-12

The simplest whole number ratio of atoms

The sum of the relative atomic masses of all of the atoms or ions in its formula

#98. What does the atomic number of an element mean?

The number of neutrons in its nucleus

The number of electrons in shells surrounding the nucleus

The number of protons in its nucleus

#99. Relative atomic mass used to have a different name. What was that name?

Molecular molar mass

Relative formula mass

Atomic weight

#100. Calcium nitrate contains the polyatomic ion NO₃⁻ (nitrate) and calcium. How many nitrate ions will be needed to make one molecule of calcium nitrate?

2

1

3

#101. Displacement reactions sometimes occur between a metal and a compound of a less reactive metal. Are these reactions endothermic or exothermic?

Exothermic

Endothermic

#102. Calculate the empirical formula of a compound which contains 5.31g of chlorine (Aᵣ - 35.453) and 8.40g of oxygen (Aᵣ - 15.999).

ClO₂

ClO₃

ClO

Cl₂O₇

#103. Which of these describes the term "rate of reaction"?

The speed at which reactants are turned into products

The rate of temperature change in the surroundings

The number of particles involved in a reaction in 1 minute

#104. Ernest Rutherford fired positive particles at a thin gold foil and showed that most of atoms is empty space. Which particles did he fire at the gold foil?

alpha particles

beta particles

gamma rays

#105. Which of the following descriptions matches the term empirical formula?

Is the sum of the relative atomic masses

Represents the actual number of atoms of each element in a molecule

Represents the simplest integer ratio of atoms or ions of each element in a compound

#106. Is it possible to control the rate of reaction?

Yes

No

#107. Why is a spark often needed to start a combustion reaction?

It removes excess nitrogen from the surrounding area, making ignition easier

It provides the activation energy needed

It releases electrons from their shells and they rapidly ignite the fuel

#108. Calculate the relative formula mass of water. Hydrogen Aᵣ = 1, Oxygen Aᵣ = 16.

enter answer here...

#109. Chemical reactions require a high enough collision energy for reactions to take place. What do we call the minimum amount of energy needed for a reaction?

The Introactive energy minimum

Reactionary energy

Activation energy

PR energy

#110. In an experiment to measure the rate of photosynthesis of pondweed in a test tube, the number of bubbles (oxygen) produced per minute is used to determine the rate of reaction. What is this experiment actually measuring?

The mass of the products of the reaction

The concentration of the products of the reaction

The mass of the reactants of the reaction

The volume of the products of the reaction

The volume of the reactants of the reaction

#111. Which geological process formed Earth's atmosphere?

Glaciation

Earthquakes

Volcanism

Continental drift

#112. Where is most of the mass of an atom?

in the nucleus

orbiting the nucleus in the electrons

#113. Will exothermic reactions continue if there is no energy input?

No, even if reactants have not run out

Yes, until reactants run out

#114. Which of the following are problems that would arise from measuring an extremely slow rate of reaction?

Select all that apply:

Very small changes are difficult to accurately measure

Very slow changes require long-term experiments - costly and may exceed human lifetimes

Extremely slow reactions do not always follow the law of conservation of energy

#115. Which of the following are effects of climate change?

Select all that apply:

Rising ocean temperatures causing coral bleaching and other adverse effects

Extinctions of species unable to migrate or adapt to higher temperatures

More extreme weather events (stronger storms, rainfall and droughts)

Lower pH of oceans due to dissolving carbon dioxide producing carbonic acid

Rising sea levels due to ice in the south pole and in glaciers melting

#116. What do group one atoms do when they bond ionically with group 7 atoms?

gain two electrons

gain one electron

lose one electron

lose two electrons

#117. Which of the following things were hypothesised by John Dalton in 1805? ? select 4 answers

Select all that apply:

atoms cannot be created or destroyed

atoms are hard cubes that can be broken down into protons, neutrons and electrons

atoms cannot be broken down into smaller parts

all matter is made up of tiny spheres called atoms

atoms in elements are identical, but elements have different types of atoms

atoms can be created and destroyed

#118. What is the electronic configuration of hydrogen?

2,1

1

1,2

2

#119. Which steps can we take to reduce the impact of climate change on humanity or prevent further climate change?

Select all that apply:

Using renewable energies instead of fossil fuels

Pumping water to the Sahara Desert and creating a new place to live

Building flood defences

Carbon capture from the atmosphere and storage underground

Cutting down forests to give humans a new place to live

Ensuring clean water supplies for vulnerable communities

#120. How many sulfur atoms will react with two lithium atoms to form an ionic compound?

2

3

1

#121. What is the relative mass of a proton?

1/1840

2

1

#122. What is meant by the term empirical formula mass?

The sum of the relative formula masses for each element in a compound, multiplied by the number of atoms of each element

The sum of the relative atomic masses of each element in a compound, multiplied by the number of atoms of each element in its empirical formula

The molecular mass, multiplied by the overall number of particles

#123. Determine the molecular formula of hydrogen peroxide which has an empirical formula of HO. The Mᵣ for hydrogen peroxide is 34. Hydrogen Aᵣ - 1, Oxygen Aᵣ - 16.

H₂O₂

HO₂

OH₂

H₂O

#124. What is the electronic configuration of fluorine?

2,8

2,9

2,7

3,1

#125. What is the chemical symbol for hydrogen?

enter answer here...

#126. Respiration from animals is a source of carbon dioxide in the atmosphere - do plants also use respiration?

only carnivorous plants perform respiration

yes

no

#127. Which of the following descriptions matches the term molecular formula?

Represents the actual number of atoms of each element in a molecule

Is the sum of the relative atomic masses

Represents the simplest integer ratio of atoms or ions of each element in a compound

Edexcel GCSE Chemistry Paper 2

Good Luck!

Results

#1. What is the chemical symbol for helium?

#2. Lead has 4 stable isotopes. ²⁰⁴Pb (abundance - 1.4%), ²⁰⁵Pb (abundance - 24.1%), ²⁰⁷Pb (abundance - 22.1%) and ²⁰⁸Pb (abundance - 52.4%). Calculate the Aᵣ of lead. Answer to 2 decimal places.

#3. In the modern periodic table, elements are arranged in increasing order of which number?

#4. What is the electronic configuration of magnesium?

#5. Calculate the empirical formula of a compound that contains 69.94g of Fe (Aᵣ - 55.85) and 30.06g of O (Aᵣ - 12.00).

#6. Temperature affects the rate of reaction. Which of the following is the correct description of what happens when temperature changes?

#7. What is the chemical symbol for lithium?

#8. What is the formula for potassium oxide? ? you might need a periodic table to answer this question

#9. Which of the following statements is accurate about group number?

#10. In the modern periodic table, what are rows and columns called?

#11. What is the charge of a neutron?

#12. What is the formula for the polyatomic ion nitrate?

#13. In which of the following are chemical properties similar in the periodic table?

#14. Greenhouse effect 1) Fill in the blanks: Energy from the sun in the form of ........ hits the Earth's surface and ....... are emitted back towards the atmosphere.

#15. Greenhouse effect 2) Fill in the blanks: Greenhouse gases such as ........... , ............. and ........... absorb infrared radiation from the Earth and re-emit it back to the Earth's surface, causing warming.

#16. Which of the following is the chemical test for oxygen?

#17. Dimitri Mendeleev developed the first periodic table. How did he arrange the elements in the table?

#18. What is the charge of a proton?

#19. Which of these reasons explains why temperature affects rate of reaction?

#20. Increasing the concentration of solutions increases the rate of reaction, why is this the case?

#21. How many atoms of potassium (group 1) are needed to bond ionically with oxygen (group 6)?

#22. Which of the following examples matches the composition of Earth's early atmosphere?

#23. What is the formula for the polyatomic ion hydroxide?

#24. What are negative ions called?

#25. What is the formula for the polyatomic ion sulfate?

#26. Why did the amount of oxygen in the atmosphere increase over time?

#27. What are positive ions called?

#28. On the early Earth, there was a lot of volcanic activity as the planet was cooling down. How can we link this to the formation of the atmosphere?

#29. What is the current composition of the Earth's atmosphere?

#30. Hydrogen has two stable isotopes, ¹H (abundance - 99.972%) and ²H (abundance - 0.001%). Calculate the Aᵣ of hydrogen. Answer to 3 decimal places.

#31. Calculate the relative formula mass of copper oxide (CuO) to 2 decimal places. Copper Aᵣ = 63.5, Oxygen Aᵣ = 16.

#32. Which type of reaction transfers energy to the surroundings?

#33. True or false - volcanism removes carbon from the atmosphere

#34. Which type of reaction takes in energy, making the surroundings cooler?

#35. Decomposers break down dead animal and plant material - what happens to the carbon inside the dead organisms?

#36. When fossil fuels are burned they release carbon into the atmosphere - which of the following are fossil fuels?

#37. Determine the empirical formula of glucose - C₆H₁₂O₆.

#38. True or false - carbon dioxide is removed from the atmosphere as it dissolves in the oceans?

#39. What is the relative mass of an electron?

#40. How did the oceans form?

#41. Where are metals and non-metals found on the periodic table?

#42. True or false. All atoms of the same element have the same atomic number.

#43. What is the name of the force that holds together ions in ionic compounds?

#44. What is the electronic configuration of a nitrogen atom? ? you might need a periodic table to answer this question

#45. Which evidence provides information about carbon dioxide concentration and global temperatures?

#46. Which three particles are atoms composed of?

#47. Which of the following statements is accurate about period number?

#48. Determine the molecular formula of glucose which has an empirical formula of CH₂O. The Mᵣ for glucose is 180. Carbon Aᵣ - 12, Hydrogen Aᵣ - 1, Oxygen Aᵣ - 16.

#49. What is the formula for the polyatomic ion sulfite?

#50. Energy is transferred between the environment and reactants during a chemical reaction. What form is this energy usually in?

#51. Reaction profiles are used to show the energy transfers during reactions. Which type of reaction is shown in this reaction profile?

#52. What evidence supports the notion that human activities are contributing to climate change?

#53. When there are more frequent collisions between particles, what will happen to the rate of reaction?

#54. Which of the following descriptions matches the Aᵣ of an element?

#55. Why may our attempts to mitigate the effects of climate change cause further damage to the environment?

#56. Chlorine has two stable isotopes, ³⁵Cl (75.77%) and ³⁷Cl (24.23%). Calculate the Aᵣ of chlorine to 2 decimal places.

#57. True or false - plants remove carbon from the atmosphere during photosynthesis

#58. Why do historical measurements by humans of global temperature have some uncertainty?

#59. Atomic number represents the number of protons in the nucleus of an atom. This means that elements further down the table have:

#60. How could we accurately monitor the rate of a reaction? ? Three answers

#61. What is the formula for the polyatomic ion ammonium?

#62. Why is there a minimum energy required for reactions to occur?

#63. Determine the empirical formula for Cyclopentane - C₅H₁₀?

#64. What is the symbol for relative atomic mass?

#65. Which type of reaction is photosynthesis?

#66. What are ions?

#67. Which of these is a fast reaction?

#68. What is the mass number of an element?

#69. What is the charge of an electron?

#70. What is the electronic configuration of boron?

#71. Isotopes of atoms have different numbers of which particles?

#72. Determine the empirical formula for Cyanuric triazide - C₃N₁₂.

#73. What is the formula for the polyatomic ion carbonate?

#74. Which of the following is the correct maximum number of electrons in the first three shells?

#75. What is the symbol for relative formula mass (also known as relative molecular mass)?

#76. What do group 2 atoms do when they bond with group 6 atoms?

#77. True or false - Precipitation reactions can be either exothermic or endothermic.