Asample of a substance has a high density, yet a low particle motion. this sample must be a

A solid

With solids the particles are very close together making the substance very dense, and because the particles are so close they don't have very much room to move, making the particle motion very low.

l dont know l am s sorry

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