Atomic Mass | MCQs

Explanation

Explanation

Explanation

• Atoms of the same element with different numbers of neutrons are called isotopes.
• Atoms of the same element have the same number of protons and electrons but different numbers of neutrons.

Explanation

Isotopes are atoms with different atomic masses that have the same atomic number.

The atoms of different isotopes are atoms of the same chemical element; they differ in the number of neutrons in the nucleus.

Isotopes:

• The isotopes are a group of atoms that have the same atomic numbers but different mass numbers.
• That means all isotopes of an element have the same number of protons in their atomic nuclei and the same number of electrons in the electron cloud surrounding the nucleus.

Difference between isotopes

• Isotopes differ in the total number of neutrons present in their respective atomic nuclei.
• Thus they have different mass numbers.
• Different isotopes of the same element are having different masses.
• Protium (1 proton,1 electron, and no neutrons), Deuterium (1 proton, 1 electron, and 1 neutron), and Tritium (1 proton, 1 electron, and 2 neutrons) are examples of isotopes of Hydrogen.

Explanation

The atomic mass (also known as atomic weight) of an element is the total mass of protons and neutrons present in the nucleus of an atom.

This includes:

• Mass of protons (which defines the element)
• Mass of neutrons (which varies in different isotopes)

Explanation

• Gram atomic mass (GAM) is the atomic mass of an element expressed in grams.
• It represents the mass of one mole of atoms of that element.

Explanation

Isotopes of an element have the same number of protons.

Explanation

• The mass number (represented by the letter A) is defined as the total number of protons and neutrons in an atom.
• Consider the table below, which shows data from the first six elements of the periodic table.
• Consider the element helium.
• Its atomic number is 2, so it has two protons in its nucleus.

Explanation

Explanation

The atomic mass (A) is the sum of protons and neutrons in the nucleus. In this case:

• Protons (Z) = 11
• Neutrons (N) = 12
• Atomic Mass (A) = Z + N = 11 + 12 = 23