Question

1. determine if the following is a physical change (p) or a chemical change (c):

a. melting ice:
b. rusting iron:
c. digesting food:
d. soured milk:
e. crumpling a sheet of aluminum foil:
f. boiling water:
g. shredding paper:
h. heating sugar to form caramel:

Explanation:

• Melting ice: Only changes the state of water from solid to liquid. No new substance is formed.
• Rusting iron: Iron reacts with oxygen and moisture to form iron oxide (rust), a new substance.
• Digesting food: Chemical reactions break down food into simpler substances.
• Soured milk: Bacteria cause chemical changes in milk, producing lactic acid.
• Crump ling a sheet of aluminum foil: Only changes the shape of the foil. No new substance is formed.
• Boiling water: Changes the state of water from liquid to gas. No new substance is formed.
• Shredding paper: Only changes the size and shape of the paper. No new substance is formed.
• Heating sugar to form caramel: Chemical reactions occur, forming new substances (caramel).

Answer:

a. P
b. C
c. C
d. C
e. P
f. P
g. P
h. C