Question

One atom has 11 protons and 13 neutrons. Another has 11 protons and 12 neutrons. Are they the same or different elements? Explain your answer

Answer 1

Answer: Both the given species are isotopes of the same element.

Explanation:

An isotope is defined as the chemical species that have the same atomic number but a different mass number.

The atom consists of 3 subatomic particles:

• Protons: They are positively charged particles present in the nucleus of an atom.
• Electrons: They are negatively charged particles present in the orbits around the nucleus of an atom.
• Neutrons: They are neutral particles present in the nucleus of an atom.

An atomic number is defined as the number of protons or number of electrons present in a neutral atom. It remains specific for a particular element.

Mass number is defined as the sum of the number of protons and neutrons present in the nucleus of an atom.

Given values:

For isotope 1:

Number of protons = 11 = atomic number

Number of neutrons = 13

Mass number = 11 + 13 = 24

For isotope 2:

Number of protons = 11 = atomic number

Number of neutrons = 12

Mass number = 11 + 12 = 23

As the atomic number of both the isotopes is the same. Thus, they belong to the same elements.