Science 10

During a chemical reaction

• atoms are destroyed

• atoms are rearranged

• elements are destroyed

• new elements are produced

Fresh fish and meat that are not stored in a refrigerator show signs of spoilage in less than a day. What has caused this spoilage?

• temperature changes

• presence of microorganisms

• oxygen in air

• all of the above

The rate of reaction increases as the temperature increases. Which of the following

statements  provides the best explanation  for this?

• At lower temperatures the particles do not collide with each other

• At higher temperatures the particles have  more energy, move faster and collide more often

• Higher temperature has higher activation energy

• Increasing the temperature increases the number of particles so they collide more often

Which of the following demonstrates that a new substance can be formed from a chemical reaction?

• blowing up a balloon

• iron bending

• milk souring

• water evaporating

Which of the following is the best evidence that rusting is a chemical property rather than a physical property of iron?

• rust can form on any iron

• rust cannot turn back into iron

• rust does not look the same as iron

• rust forms slowly

Which of the following is the best evidence that rusting is a chemical property rather than a physical property of iron?

• rust can form on any iron

• rust cannot turn back into iron

• rust does not look the same as iron

• rust forms slowly

Which of the following is the best evidence that rusting is a chemical property rather than a physical property of iron?

• rust can form on any iron

• rust cannot turn back into iron

• rust does not look the same as iron

• rust forms slowly