Which of these elements has four valence electrons? hafnium radon silicon sulfur

Answer : The elements that has four valence electrons are hafnium (Hf) and silicon (Si).

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.

Valence electrons or outermost electrons : They are electrons in an atom that participate in bonding.

(a) Hafnium is a metal that belongs to group 4 and period 6. The atomic number of Hafnium is, 72.

The electronic configuration of hafnium will be,

The total number of valance electrons = [2 + 2] = 4

(b) Radon is a noble gas that belongs to group 18 and period 6. The atomic number of radon is, 86.

The electronic configuration of radon will be,

The total number of valance electrons = [2 + 6] = 8

(c) Silicon is a non-metal that belongs to group 14 and period 3. The atomic number of silicon is, 14.

The electronic configuration of silicon will be,

The total number of valance electrons = [2 + 2] = 4

(d) Sulfur is a non-metal that belongs to group 16 and period 3. The atomic number of sulfur is, 16.

The electronic configuration of sulfur will be,

The total number of valance electrons = [2 + 4] = 6

Hence, from this we conclude that, the elements that has four valence electrons are hafnium (Hf) and silicon (Si).

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