Atomic Number and Mass Number

What is Atomic Number?

Atomic number of an element is the total number of protons that are present in the atom. The atomic number of an atom explains the properties of an element, it is represented using the letter “Z”. All the elements are arranged in the periodic table on the basis of their atomic number....

What is Mass Number?

Mass Number of an atom also called Atomic Mass Number is the total number of protons and neutrons present in an atom. Rutherford in his gold foil experiment concluded that the mass of the atom is concentrated in a small region called the Nucleus which is positively charged. Later on, it was found that the nucleus consists of two particles Protons and Neutrons. Neutrons and Protons are together called nucleons. Proton is a positively charged subatomic particle while Neutron is a neutral particle. The mass of Proton and Neutron is the same and is equal to 1.67 ⨯10-27 kg. Compared to Proton and Neutron, an electron is 1000 times lighter as the mass of an electron is 9.1 ⨯ 10-31 kg...

How to Find Mass Number?

Mass Number of an atom is the total number of protons and neutrons present in the mass number. Mass Number can be calculated using the following steps:...

Mass Number of Elements

As we have already learned that Mass Number of an Element is the sum total of the number of protons and neutrons. Mass Number of elements is denoted by the letter ‘A’. Let’s learn the mass number of some elements....

List of Mass Numbers of First 20 Elements

The mass number and the atomic number of different elements of the periodic table are as follows,...

Atomic Number and Mass Number

Atomic Number is the number of protons in an atom while Mass Number is the total number of protons and neutrons in an atom. Atomic Number is denoted by the letter ‘Z’ and the Mass Number is denoted by the letter ‘A’. Atomic Number and Mass Number of an element are different however this is not the case always. In the case of Hydrogen, the Atomic Number and Mass Number both are equal to 1....

Representation of an Atom

The atom of any element is represented by using the English Alphabet and its notation is discussed in the image below,...

Atomic Mass vs Mass Number

Atomic Number and Mass Number both indicate the mass of an atom but they have some differences between them. Let’s learn the difference between Atomic Mass and Mass Number through the following table:...

Solved Examples on Mass Number

Example 1: Find the number of electrons, protons, and neutrons of an atom with Atomic Number (Z) 13 and Mass Number (A) 26....

Atomic Number and Mass Number – FAQs

1. Define Mass Number....