Question

What is the mass number and the atomic number of Boron-11?

Answer 1

Step 1. Formula for atomic number:

• Atomic number$\left(\mathrm{Z}\right)=$Number of protons in the nucleus of an atom

Step 2. Mass number of Boron-11:

• The name Boron-11 is used to designate an isotope of boron that has a mass number equal to 11.
• So, the mass number of Boron-11 is $11$.

Step 3. Atomic number of Boron-11:

• The number of protons in Boron-11 is $5$.
• So, the atomic number of Boron-11 is $5$.

Hence, the mass number and the atomic number of Boron-11 is $11$and $5$ respectively.