Download Physical and Chemical Changes

Physical and Chemical Changes
1. Carbohydrates are large, complex molecules that can be broken down into
smaller molecules called what? What type of compound is this?
Carbohydrates are broken down into glucose molecules, which are a type of sugar.
2. Which element is found in abundance in the human body, but NOT found in
abundance in the Earth?
Carbon
3. What energy transformation is taking place when an animal eats food so it can
keep warm?
Chemical energy is transformed into thermal energy
4. What elements can organic compounds contain? List names, not symbols.
Organic compounds MUST contain Carbon and Hydrogen; they may also contain
Oxygen, Nitrogen, Sulfur, Phosphorus
5. What is the main function of the digestive system?
The main function of the digestive system is to break down large molecules into smaller
ones.
6. What type of energy conversion occurs when energy from food is stored as fat?
Chemical energy is transformed into chemical energy
7. What are some physical changes while you eat?
Physical changes to food while eating occur through chewing/teeth tearing and
peristalsis (muscle contractions in esophagus and intestines).
8. Which element is found in abundance in both the human body and in the
Earth?
Oxygen is found in abundance (meaning there is a lot of it) in both the human body and
the Earth’s crust.
9. What are some chemical changes while you eat?
Chemical changes while you eat are food mixing with saliva and gastric or stomach juice
or acid which breaks down fats and proteins.
10. Which of the following are chemical changes, physical changes, or both?
 chewing and mixing food with saliva – both chemical and physical
 movement of food through peristalsis – physical
 reaction of food with hydrochloric acid – chemical
 interaction of food with bile – chemical