Question

An atom of lithium has three protons and four neutrons in its nucleus. What is its atomic number and mass number?

Answer 1

In the given information, it is stated that an atom of lithium has three protons and four neutrons in its nucleus.

1. Atomic Number (Z): The atomic number represents the number of protons in an atom's nucleus. Since the atom of lithium has three protons, the atomic number of lithium is 3.

2. Mass Number (A): The mass number represents the sum of protons and neutrons in an atom's nucleus. In this case, lithium has three protons and four neutrons, so the mass number is 3 + 4 = 7.

To summarize: Atomic Number (Z) = 3 Mass Number (A) = 7

Thus, the atomic number of lithium is 3, and its mass number is 7.