Answer:
Several of the nonmetals are gases in their elemental form. Elemental hydrogen (H, element 1), nitrogen (N, element 7), oxygen (O, element 8), fluorine (F, element 9), and chlorine (Cl, element 17) are all gases at room temperature, and are found as diatomic molecules (H2, N2, O2, F2, Cl2).
Explanation:
Answer:
a) the atomic number is 15
b) the mass number is 15+16 = 31
c) element is phosphorus
d)Group 15 period 3
Answer: The first steps
Explanation: science