Question

In the symbol 42He, the subscript 2 is the _____ for helium and the superscript 4 is the _____ for helium. atomic mass; atomic number atomic number; atomic mass mass number; atomic number atomic number; mass number

Answer 1

Mass number ; atomic number

Answer 2

Answer:

2 is the atomic number while 4 is the mass number.

Explanation:

The symbol of an element is Z X A. Where Z is the number of protons or called atomic number of the element and A be the sum of number of protons and neutrons or called mass number of that element,

Here 42He,

Z = 2, it means atomic number is 2, which shows that number of proton are 2.

A = 4, it means mass number, which shows that the sum of number of neutrons and protons are 4.