Choose the appropriate electron configuration for an element that has electrons in six orbitals. Group of answer choices

1s2 2s2 2p6 3s2 3p6

1s2 2s2 2p6 3s2 3p4

1s2 2s2 2p6 3s1

1s2 2s2 2p5

Explanation:

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.  

it is the most commonly accepted one