The element copper has naturally occurring isotopes with mass numbers of 63 and 65. The relative abundance and atomic masses are 69.2% and 30.8% respectively. Calculate the average atomic mass of copper.

Achange in the number of neutrons in an atom will change an blank . when the number of protons changes in an atom, a new element will form.

How many moles of oxygen react with 12 moles of aluminum

What happens to the concentration of hydronium ions as the ph of a solution increases? a. hydronium ion concentration stays the same b. hydronium ion concentration decreases c. hydronium ion concentration increases