A or D I think but go with A it makes more since
Answer:
The approximate mass of beryllium is 9.0045 u.
Explanation:
Given data:
mass of helium= 4.002 u
mass of beryllium which is 2.25 times of mass of helium= ?
Solution:
we will multiply the mass of helium with 2.25 times,
4.002 u × 2.25 = 9.0045 u
so the mass of beryllium atom would be 9.0045 u.
Answer:
Ununoctium
Explanation:
It's at the very end of the periodic table