Consider a wooden chair and a balloon. What do these two objects always have in common?

A. Both are made of the same number of atoms.

B. Both have the same mass number.

C. Both are made of the same kind of atom.

D. Both are made of atoms.

When the chemicals iron sulfide (fes) and hydrochloric acid (hcl) are combined, bubbles appear from the mixture. 1. does the appearance of bubbles indicate a physical or chemical change? 2. why do the bubbles indicate this change? 3. what property is this?

What is a substance? a. a physical property of matter b. a chemical property of matter c. an element or compound that cannot be physically separated d. characteristics used to tell the difference between mixtures

A0.100-kilogram apple hangs in a tree 1.50 meter above the ground. ignore frictional effects, the total mechanical energy of the apples is