Please help
I need I badly or I'm going to fail

What are the percent by mass of copper in penny lab

Which sentence about particles in matter is true? a. atoms are present in solids and liquids but not in gases. b. the particles of matter are in constant motion. c. the same kinds of atoms are found in different elements. d. when a solid changes to a liquid, the sizes of the particles change.

What is the atomic number of an atom that has 6 protons