Question

31
The following table shows the position of five clements A, B, C, D and E in
the modern periodic table.
1
2
3 to 12 13
14 | 15
16
17
18
Group-
Period
2
A
B
С
3
D
E
Answer the following giving reasons
(1) Which element is a metal with valency two?
(11) Which element is least reactive?
(ii) Out of D and E which element has a smaller atomic radius?​

Answer 1

Answer:

(1) Beryllium (atomic number 4)

(2) The group 18 is the least reactive

(3) E has a smaller atomic radius

Answer 2

Answer:

(1) Beryllium (Atomic number 4) is a metal with 2 valency.

(2)Element E is least reactive.

(3) Out of D and E, element E has a smaller atomic radius.

Explanation:

Beryllium metal

Beryllium is lightest metal in the Alkaline earth metal which is a silvery white/gray coloured metal with brittle in nature. It has high thermal conductivity and it can resist the attack of concentrated nitric acid ,It has high melting point. Beryllium is non magnetic in nature.

Modern periodic table

• The modern periodic table is a table form arrangement of the chemical elements, organized on the basis of their atomic number, electronic configurations, and chemical properties.
• It shows the elements grouped into periods (rows) based on their electron configurations and into groups (columns) based on their electron configurations and chemical properties.

To learn more about thermal conductivity, refer these links.

https://brainly.in/question/35915367

https://brainly.in/question/16172994

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