Question

the total number of protons and neutrons in an atom is called its mass number which is specified by the symbol _______.
n
z
a

question 9
1 pts
the mass number is equal to ______________.
number of protons + number of neutrons
number of protons + number of neutrons + number of electrons
number of protons + number of electrons
number of neutrons
number of protons

Explanation:

In atomic - structure, the mass number of an atom is the sum of protons and neutrons. It is denoted by the symbol A. And by definition, mass number = number of protons + number of neutrons.

Answer:

First question: A. A
Second question: number of protons + number of neutrons