Question

Both Question 4 and 5

Answer 1

Explanation:

4. 1.Protons 9

Electrons 9

Neutrons 10

2. Protons 20

Electrons 20

Neutrons 20

5. 1. Isotopes are the elements which have same atomic no. but different mass nos.

2. Isotope (FROM ABOVE)

Isobar are the elements which have same mass no but different atomic nos.

Answer 2

ANSWER 4 =>

(I) protons = atomic number = 9

electrons= protons = 9

neutrons= mass number - protons

= 19- 9 = 10

(ii) protons= 20

electrons= 20

neutrons = 40-20 = 20

ANSWER 5=>

(I) Isotopes - these are the elements having same atomic number but different mass number.

(ii) In isobar, elements have same mass number but different different atomic number.

example- sodium and magnesium have same mass no. (24) but different atomic number.

In istopes, elements have same atomic number but different mass number.

example- hydrogen, deuterium and tritium have same atomic number(1) but different in mass no.

Hope this answer will be helpful to you dear....

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