C) Noble gases
The six noble gases are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). Their atomic numbers are, respectively, 2, 10, 18, 36, 54, and 86.
Answer:
95% Copper and 5% Zinc
Explanation:
Easy stuff read in the chemistry book...
<span>For isotopes of any element, the number of protons remains the same, BUT the number of neutrons changes. Since each of the isotopes listed is phosphorus, All three have 15 protons. (They have 16, 17 and 18 protons respectively.)</span>