Science 20F Cluster 2 Chemistry in Motion

Which of the following is the smallest particle of an element that can exist by itself?

• ion
• atom
• molecule
• compound

Which of the following are responsible for bonding?

• nuclei
• protons
• neutrons
• electrons

Use the following Bohr model of an element to answer the question. Which of the following does the Bohr model represent?

• a neon atom
• a sodium ion
• a sodium atom
• a fluorine atom

In which of the following do covalent bonds hold the atoms together?

• silver
• calcium carbonate
• silicon tetrafluoride
• magnesium bromide

Which of the following is the formula for the compound formed by ammonium and dichromate?

• NH4Cr2O7
• (NH4)2CrO4
• NH4 (Cr2O7) 2
• (NH4) 2Cr2O7

In the name arsenic (III) chloride, what does the Roman numeral reveal about arsenic?

• it has an ion charge of 3-
• it has an ion charge of 3+
• it has gained three electrons
• it can form three positive ions

Use the following unbalanced equation to answer the question. Which of the following sets of coefficients will balance the equation?

• 1, 4, 5, 1
• 1, 5, 4, 1
• 1, 3, 5, 2
• 1, 4, 2, 1

A solution of sodium sulphide is mixed with a solution of copper(II) nitrate. A precipitate of copper sulphide is formed in a solution of sodium nitrate. What are the reactants in this chemical reaction?

• Na2S and CuS
• CuS and NaNO3
• Na2S and Cu(NO3)2
• Na2SO4 and Cu2NO3

A piece of aluminum metal is placed in a solution of sulphuric acid, H2SO4. A compound, aluminum sulphate, forms and bubbles are seen going to the surface. What type of gas formed during this reaction?

• oxygen
• hydrogen
• carbon dioxide
• carbon monoxide

What happens to the number of H+ after H2SO4 is added to water?

• it increases
• it decreases
• it stays the same