Question

calculate the number of protons ,electrons,neutrons using atomic number 3 and mass number is 7 . find valency and valence electrons with help of electronic configuration and find out the element.​

Answer 1

Answer:

Valency is the combining capacity of one element with the other. If the number of valence electrons are 1, 2, 3, 4 then the valency is the same as the number of electrons. If the number of electrons are more than 4 then the valency is 8-(no. of outermost electrons). The electronic configuration of X is 2, 3. The electronic configuration of Y is 2, 6. The electronic configuration of Z is 2, 8, 5. The atomic number is the number of protons and the mass number is the sum of both protons and neutrons.

X

Y

Z

Valency (no. of electrons in outer shell that can be lost)

3

2

3, 5

Atomic no.(no. of protons)

5

8

15

Mass no.(sum of protons and neutrons)

11

18

31

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