1. A neutral atom has a mass number of 128 and an atomic number of 52. Use this information to fill in the table below.
Question Answer
How many protons are in this atom? How do you know?

How many electrons does the atom have? How do you know?

Calculate the number of neutrons – show your work.

If this atom becomes an ion with a +4 charge, how many electrons would the ion have?
This atom has an isotope with one extra neutron – what is its mass number?