Question

An atom of an element contains 9 protons and 10 neutrons.
(i) What is the atomic number of the element?
(ii) What is the mass number of the element?
(iii) Write the electronic configuration of the element.
(iv) Identify the element

Answer 1

1.atomic number of the element is 9.
2.mass number=number of protons +number of neutrons,
mass number=9+10=19.so mass number of the element is 19.
3.k shell-2,L shell-7, valency is -1.
4.the element is fluorine.

Answer 2

Hi friend ,

(i) Atomic no. of an element = No. of protons
Atomic no. = 9

(ii) Mass no. of an atom = No. of protons + No. of neutrons
Mass no. = 9+ 10 = 19u
Mass no. = 19u

(iii) Electronic configuration = 2,7

(iv) The element is fluorine.

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