Question

four elements P, Q, R & S have atomic numbers 12, 13, 14 and 15 respectively. Answer the following;
1. what is the valency of Q?
2. classify these elements as metals and non metals.
3. which of these elements will form the most basic oxide?

Answer 1

Given:

Atomic number of P = 12

Atomic number of Q = 13

Atomic number of R = 14

Atomic number of S = 15

To find:

1. Valency of Q = ?
2. Classify these elements as metals and non metals.
3. which of these elements will form the most basic oxide?

Solution:

From the given atomic numbers, the elements are identified as:

P = Magnesium

Q = Aluminium

R = Silicon

S = Phosphorous

Valency of element Q

• From the atomic number of Q, it is identified as Aluminium.
• As its atomic number is 13, its electron distribution pattern is 2,8,3.
• As it has 3 electrons in its outer most shell, it readily loses them to attain octet.
• Thus its valency is identified as +3.

Classification of given elements

• The given elements are Magnesium, Aluminium, Silicon and Phosphorous.
• Among them, Magnesium and aluminium are metals, Silicon is a metalloid and Phosphorous is a non metal.

Formation of the most basic oxide

• Metals are the elements which form basic oxide. Among the given series, magnesium and Aluminium are metals.
• The most basic oxide is formed by magnesium because the metallic character decreases from beginning to end.
• In the periodic table, Aluminium comes next to Magnesium. Thus the metallic character is more in magnesium than aluminium. Thus it forms the most basic oxides.

Learn more about such concept

Atomic number of a few elements are given below

10, 20, 7, 14

https://brainly.in/question/119496

Given below are some elements of the modern periodic table. Atomic number of the element is given in the parentheses : A(4), B(9), C(14), D(19), E(20) (a) Select the element that has one electron in the outermost shell, Also write the electronic configuration of this element

https://brainly.in/question/281062

Answer 2

1] Valency of Q = +3

2] Metals - Magnesium and aluminum

Non-metals - phosphorous

Metalloid - silicon

3] Magnesium