Photosynthesis

How many atoms of hydrogen are in CH₃OH?

• 1

• 2

• 3

• 4

How many atoms of carbon are in 2C₂H₂?

• 2

• 4

• 6

• 8

Which of the following statements are true according to the Law of Conservation of Mass?

• Every atom that exists today existed 4 billion years ago

• New atoms are created every passing second

• Atoms are destroyed in nuclear reactions

• None of these statements are true

Oscar heated a 10 g sample of a compound in an open container. A chemical reaction occurred. He measured the mass of the sample again after the reaction, and he found that the mass was 8.6 g.

Which of the following statements explains why the mass decreased?

• Oscar made a mistake in his experiment.

• The reaction occurred in a closed system.

• The reaction occurred in an isolated system.

• Some of the reactants were probably gases and escaped the container.

Mark adds 15 g of baking soda to 10 g of acetic acid in a beaker. A chemical reaction occurs and a gas is given off. After the reaction, the mass of the products remaining in the beaker is 23 g.

What is the mass of the gas given off?

• 25 g

• 2 g

• 5 g

• 33 g

Which of the following statements describes what happens to atoms during a chemical reaction? Select all that apply.

• New atoms are created.

• New substances are created.

• Bonds break and form.

• Atoms break apart and rearrange.

Which are the products of photosynthesis? Select all that apply.

• oxygen

• water

• carbon dioxide

• glucose

Which are the reactants of photosynthesis? Select all that apply.

• carbon dioxide

• glucose

• water

• oxygen

Which product of photosynthesis is a waste product?

• oxygen

• carbon dioxide

• glucose

• water

Which of the following describes the energy transformation that occurs during photosynthesis?

• Thermal (heat) energy is transformed into kinetic energy.

• Potential energy is transformed into kinetic energy.

• Chemical energy is transformed into thermal (heat) energy.

• Light energy is transformed into chemical energy.