Respuesta :

jessiraubenolt

Explanation:

9/4 Be +2 (the 9 and 4 are stacked next to Be). Atomic #: 4

Mass #: 9, # protons: 4, # neutrons: 5, #electrons: 2.

31/15 P (31 is stacked over 15 next to the P). Atomic #: 15,

Mass #: 31, # protons: 15, # neutrons: 16, # electrons: 15.