6. When an element is shown with a mass number and atomic number, which number is placed on top?
- a sum of both
- mass
- neither
- atomic
7. How many protons would oxygen have?
- 9
- other
- 8
- 16
8. What is an isotope?
- atoms of different elements with the same atomic number
- atoms of the same element with different numbers of neutrons
- atoms of the same element with different atomic numbers
- atoms of different elements with the same number of neutrons
