How is a chemical change different from a physical change?

Two things that biomedical has invented or innvated

What are the charges of the subatomic particles by choosing the answer from the drop down menu. protons have a (+1,0,or-1). (protons,neutrons,electrons) have a 0 charge. 3.) electrons have a (+1,0,-1)

What are scientists who study fossils called? ( a ) astronomers. ( b ) biologists. ( c ) geologists. ( d ) paleontologists.