Question

एक परमाणु का इलेक्ट्रॉनिक विन्यास 2, 8, 7 है।
(a) इस तत्व की परमाणु-संख्या क्या है?
(b) निम्न में किस तत्व के साथ इसकी रासायनिक समानता होगी? (परमाणु-संख्या कोष्ठक में दी गई है) N(7) F(9) P(15) Ar(18)

Answer 1

The electronic configuration of an atom is 2, 8, 7.  

(a) What is the atom-number of this element?  

(b) Which of the following elements has its chemical similarity? (Atomic number is given in parentheses) N (7) F (9) P (15) Ar (18)

ANSWERS :

a ) The atomic number of an element is the number of protons present in an atom.

The number of atoms present is equal to the number of electrons present in the element.

The number of electrons = 2 + 8 + 7 = 17

The number of atoms will also be 17.

So atomic number is 17 .

b ) Answer is chlorine F ( 9 ) .

It is because configuration of F = 2 , 7 .

These have the same valence electrons and hence they are similar.

Answer 2

✌️✌️Hallo ✌️✌️
Answer✍️✍️

☺️a-17 is the number of compounds.
☺️B-. F(9)

thank❤️