Chapter 8
Journey Inside the Atom
CBSE Class 9
Science Solutions
Educart Science class Class 9 NCERT Exemplar cover
Question:

The composition of the nuclei of three atomic species X, Y, and Z are given as follows.

X Y Z
Number of protons 18 17 17
Number of neutrons 19 18 20

Explain the relation between the following:
(A) Y and Z
(B) Z and X

Answer: Verified

(A) Y and Z are isotopes because they have the same number of protons (atomic number 17) but different numbers of neutrons (18 and 20), resulting in different mass numbers.

(B) Z and X are isobars because they have the same mass number (37) but different atomic numbers.

For Z, mass number = 17 + 20 = 37

For X, mass number = 18 + 19 = 37

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More NCERT Questions
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