Balance the equation choose the coefficient for blank 2 ( in front of the H2) C + H2 ---> CH4 A. 0
B. 1
C. 4
D. 2

a electronegativity decreases beacuse the size of nucleus is bigger.

i think it's c. if you look search electronic symbol on google and then click on wiki it shows you a

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