Question

element are identified by atomic number not by the mass no.Justify the statement.​

Answer 1

Answer:

They are both the same element, i.e. He, but with different mass numbers. So the mass number alone cannot uniquely identify an element. But the number of protons in the nucleus identifies it uniquely. In addition, if the atom is neutral, then the atomic number also equals the number of electrons in its orbitals.

Answer 2

$\huge\fcolorbox{black}{lime}{Answer}$

• They are both the same element

• But with different mass numbers.

• So the mass number alone cannot uniquely identify an element.

• But the number of protons in the nucleus identifies it uniquely.

• In addition, if the atom is neutral, then the atomic number also equals the number of electrons in its orbitals.