What are the atomicity of the 20 elements of periodic table?

Answer 1

H-2

He-

Li-2

Be-

B-2

C-2 or as diamond

N-2

O-2,3

F-2

Ne-

Na-

Mg-

Al-

Si-

P-

S-8

Cl-2

Ar-

K-

Ca-

Answer 2

The Periodic Table contains elements with varying atomicity, but typically elements are found in nature as individual atoms (atomicity of 1). Some elements, like oxygen and nitrogen, exist as diatomic molecules (atomicity of 2). Others, like phosphorus and sulfur, exist as polyatomic molecules (atomicity of 4 or more).