Question

B) An element X has mass number 35 and atomic number 17.
Answer the following questions.
i) What is the number of neutrons present in the nucleus of the atom of above
element?

ii) Write the number of valence electrons present in the atom of the above element
and write its valency?
iii) Name the element 'X'.​

Answer 1

Answer:

1.The number of neutrons within the nucleus of a given atom can be found by subtracting the atomic number from the atomic mass. The mass number is the sum of protons and neutrons. To find the number of neutrons, subtract the atomic number, the number of protons, from the mass number.

2.Counting along a row from the left gives the number of valence electrons. Titanium is 4 elements from the left and has 4 valence electrons. It is in a row corresponding to n=4 so its electronic configuration as a neutral atom is [Ar]4s24d2.

3.

Since element X belongs to 3rd period and group 16 that means it has 3 shells and 6 valence electrons so its electronic configuration will be 2, 8, 6. Hence element X is sulphur (S) and it is non-metallic.

Explanation:

I hope I am solve your problem

Answer 2

Answer:

Explanation:

(i) No. of neutrons present in the nucleus = Mass No. - No. of protons

                                                                     =  35 - 17 = 18

(ii) Electronic configuration

=>  2,8,7

The outermost shell therefore contains 7 valence electrons

It needs 1 more electron to be stable so its valency is -1

(iii) The element x is Chlorine

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