Which two statements describe a mixture? A. Jt is a pure substance.
B. Its parts can be separated using physical means.
C. It includes atoms of different elements.
D. It can result from chemical bonding.

that's what i got you can count the number of atoms

atomic mass = 39

number of neutrons = 20

number of protons= 19

electronic configuration = 1s2 2s2 2p6 3s2 3p6 4s1

the number of electron in first shell = 2

number of electrons in n=3 shell = 8