A double replacement reaction can be best described as a reaction in which a substitution takes place. two atoms of a compound are lost. ions are exchanged between two compounds. electrons are exchanged between two 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

(b) which contains higher levels of vitamin b, oranges or spinach?

explanation:

you can eliminate a, c, and d because they are questions based on opinions.