A is your answer.
On the periodic table the atomic number is the number of protons inside the nucleus.
The answer is 2.138 g of H2
Answer:
The first energy level is closest to the nucleus. The second energy level is a little farther away than the first. ... The electrons in the energy level farthest from the nucleus are called valence electrons. Atoms in the same column (group) in the periodic table have the same number of valence electrons.
Explanation:
1s2 2s2 2p6 3s2 3p6 4s1
s orbital can hold 2 electron
p orbitals can hold 6 electron