Question

Make the correct choices in the following:
(a) In one atom of copper (mass number 63, atomic number 29) there are

Options

• 63 protons and 29 neutrons.

• 63 protons and 29 electrons.

• 29 protons and 29 neutrons.

• 29 protons and 29 electrons.

• 29 protons and 63 neutrons.

Answer 1

 Mass number of copper = 63
Atomic number of copper = 29
As atomic number of element gives number of proton and electrons while mass number of element gives number of protons +number of neutrons.
So, number of protons in copper = atomic number of copper = 29.
Number of electron in copper = number of protons in copper =29.
Number of neutrons = mass number atomic number = 63 29 =34.
So answer is (iv) as copper contains 29 protons and 29 electrons.