1. What particle determines the atomic number of an atom?

2. Atoms always have the same number of what two atomic particles?

3. The number of what atomic particle varies between different isotopes of the same element?

4. What characteristic of an element differs between isotopes?

5. In the isotope Carbon-14, what does the number 14 represent?

6. What is the name given to the element hydrogen when it has no neutrons?

7. True or False: Most elements only have 1 or 2 isotopes and several elements do not have any isotopes.

8. Which of the following is true about unstable isotopes?

9. What element has the most stable isotopes?

10. What is the nickname for water made with the Hydrogen isotope deuterium?