Question

The atomic number of some elements is given as $10,20,7,$ and$14$. Identify the group number of these elements in the periodic table

Answer 1

Group number:

1. A group is a periodic table vertical column. There are a total of $18$ groupings.
2. The group number can be calculated by the electronic configuration of the element.
3. If the element belongs to the s-block group number is equal to its number of valence shells.
4. For p block elements group number$=$number of valence electron$+10$
5. For d-block elements: group number$=$number of electrons in $(\mathrm{n}-1)\mathrm{d}$subshell$+$number of electrons in $\mathrm{ns}$ the subshell
6. For f-block elements the group number is always$3$.

Neon:

1. It is a chemical element with an atomic number$=10$ and is represented by $"\mathrm{Ne}"$
2. It is a colorless, odorless inert gas.
3. Its electronic configuration is $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^6$
4. It is a p-block element with valence electron $=8$
5. Group number $=10+8\Rightarrow 18$

Calcium:

1. It is a chemical element with an atomic number$20$ and is represented by $\mathrm{Ca}$
2. It is a metal that is reactive when exposed to air.
3. Its electronic configuration is $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}4{\mathrm{s}}^2$
4. It is an s-block element with valence electron$=2$
5. Group number$=$Valence electron i.e. $2$

Nitrogen:

1. It is a chemical element with an atomic number $7$and is represented by $\mathrm{N}$
2. It is a non-metal and a common element in the universe.
3. Its electronic configuration is $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^3$
4. It is a p-block element with valence electron$=5$
5. Group number$=10+5\Rightarrow 15$

Silicon:

1. It is a chemical element with an atomic number $14$and is represented by $\mathrm{Si}$
2. It is a hard, crystalline metalloid that is a semiconductor in nature.
3. Its electronic configuration is$1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^2$
4. it s a p-block element with valence electron$=4$
5. Group number$=10+4\Rightarrow 14$

Therefore, the group number of elements having atomic numbers $10,20,7,$ and$14$ is $18,2,15,$and $14$