Question

The mass of one helium atom is

• A. $2\mathrm{amu}$
• B. $3\mathrm{amu}$
• C. $4\mathrm{amu}$
• D. $8\mathrm{amu}$

Answer 1

The correct option is C

$4\mathrm{amu}$

Explanation for correct option:

(c) $4\mathrm{amu}$

Step 1: Finding the entities given.

We know that in Helium

• number of proton = $2$
• number of neutron = $2$

Step 2: Finding the mass of 1 helium atom

• Hence, mass of $1$ helium atom becomes $2+2=4\mathrm{amu}$
• Hence this option is correct

Explanation for incorrect options:

Since, the mass of one helium atom is $4\mathrm{amu}$. Therefore, options (a), (b) and (d) are incorrect.

Hence the correct option is (c ) $4\mathrm{amu}$