# What does the mass number identify?

## What does the mass number identify?

An element’s or isotope’s mass number tells how many protons and neutrons in its atoms.

## What is the mass number same as?

The mass number is the sum of the number of protons and neutrons in an atom. It is a whole number. The atomic mass is the average number of protons and neutrons for all natural isotopes of an element.

What is mass number explain with example?

(ii) Mass number: It is the sum of the number of neutrons and the number of protons. For example, the atomic number of magnesium is 12 which is equal to the number of protons, the number of neutrons of magnesium is 12. The mass number is equal to 24 (12+12).

### What is mass number give two examples?

ii) Mass number is the number of protons and neutrons in the nucleus taken together. For example, mass number of sodium is 23 g/mol. iii) Isotopes are elements with the same atomic number but different mass numbers. Example, hydrogen has 3 isotopes – protium (1H1), deuterium (2H1) and tritium (3H1).

### Why is it called a mass number?

The mass number of an element is named as such because it gives the mass of the total number of protons and neutrons in an element.

What subatomic particle identifies atoms?

proton
The proton identifies an atom as that of a particular element. The atomic number is equal to the number of protons in the nucleus of an atom.

## Why is the mass number always a whole number?

Mass number is always a whole number because it represents the number of protons plus the number of neutrons of an isotope. However atomic mass is different! This is a weighted average (it takes into account the percentage of each isotope) and it is not a whole number!

Why is this number called the mass number?

Therefore, the mass number can also be given as the total number of nucleons present in the nucleus of an atom. This is called the mass number because it determines the mass of an atom . The mas of an atom is the total mass of the protons and the neutrons of that atom.

### How does the mass number determine?

Mass number is an integer equal to the sum of the number of protons and neutrons of an atomic nucleus. The mass number allows enable us to tell the difference between elements with a different number of neutrons, called isotopes. The mass number is a count and is unitless.

### What is the information given by the mass number?

The mass number is a count of the total number of protons and neutrons in an atom’s nucleus. The mass number is the sum of the number of protons and neutrons in an atom. It is a whole number. The atomic mass is the average number of protons and neutrons for all natural isotopes of an element.