Question

The diagram below represents the nucleus of an atom. What are the atomic number and mass number of this atom?

The atomic number is 11 and the mass number is 19.
The atomic number is 9 and the mass number is 20.
The atomic number is 9 and the mass number is 19.
The atomic number is 11 and the mass number is 20.

Answer 1

The atomic number is 9 and the mass number is 20.

Step-by-step explanation:

Answer 2

B. The atomic number is 9 and the mass number is 20

Step-by-step explanation:

The number of protons is 9

=> atomic number is 9

The total of neutron + proton = 11 + 9 = 20

=> mass number is 20