Which element has six valence electrons in each of its atoms in the ground state? (1)se (2)as (3)kr (4)ga

Answer : The correct option is, (1) Se

Explanation :

Electronic configuration : It is defined as the representation of electrons around the nucleus of an atom.  

Number of electrons in an atom are determined by the electronic configuration.

Atomic number : It is defined as the number of electrons or number of protons present in a neutral atom.

(1) The given atom is, selenium (Se)

Atomic number of Se = 34

Number of electrons = 34

The electronic configuration of selenium atom is,

Number of valance electrons = 6

(2) The given atom is, arsenic (As)

Atomic number of As = 33

Number of electrons = 33

The electronic configuration of arsenic atom is,

Number of valance electrons = 5

(3) The given atom is, krypton (Kr)

Atomic number of Kr = 36

Number of electrons = 36

The electronic configuration of krypton atom is,

Number of valance electrons = 8

(4) The given atom is, gallium (Ga)

Atomic number of Ga = 31

Number of electrons = 31

The electronic configuration of gallium atom is,

Number of valance electrons = 3

Hence, from this we conclude that the selenium element has six valence electrons in each of its atoms in the ground state.