An element 'X' belongs to Group 13 and Period 3 of the Modern Periodic Table. (a) What is the atomic number of element 'X'? (b) Write its electronic configuration. (c) What is the formula of the oxide formed by element 'X'? (d) Is element 'X' a metal, non-metal, or metalloid?

Question

Accepted Answer

To find the properties of element 'X', let's use its position in the Modern Periodic Table.

(a) Finding the Atomic Number:

The element belongs to Period 3, which means it has 3 electron shells (K, L, and M shells).
The element belongs to Group 13. For elements in groups 13 to 18, the number of valence electrons is calculated as (Group Number - 10).
Valence electrons = 13 - 10 = 3.
Since it is in Period 3, the first two shells (K and L) are completely filled with 2 and 8 electrons respectively.
The third (outermost) shell contains 3 electrons.
Total electrons = 2 (K shell) + 8 (L shell) + 3 (M shell) = 13.
Therefore, the atomic number of element 'X' is 13 (The element is Aluminium, Al).

(b) Electronic Configuration:

With an atomic number of 13, the distribution of electrons in shells (K, L, M) is:
K shell = 2
L shell = 8
M shell = 3
Electronic Configuration = 2, 8, 3

(c) Formula of Oxide Formed:

The valency of element 'X' is equal to the number of valence electrons in its atom, which is 3.
Oxygen belongs to Group 16, and its valency is 2.
Using cross-valency method:
- Element 'X' has valency: +3
- Oxygen has valency: -2
- Formula: $\text{X}_2\text{O}_3$
Therefore, the formula of the oxide is $\text{Al}_2\text{O}_3$ (Aluminium oxide).

(d) Nature of the Element:

Element 'X' (Aluminium) is located on the left side of the periodic table with 3 valence electrons, which it tends to lose easily to form positive ions.
Therefore, element 'X' is a metal.