# Isobar isotope isotone isoelectronic species

## What are isobar isotope isotone isoelectronic species

Here in this article you will learn about isobar isotope isotone isoelectronic species with different examples. You will also learn about isobar isotope isotone isoelectronic species with the help of notes and video given below.

### What are isotopes ?

Sometimes atoms of the same element contain the same number of protons but different number of neutrons. Consequently, they have same atomic number but different mass number.

As we know,

Atomic number of an element = total number of protons present in the nucleus = total number of electrons present in the neutral atom

Mass number of an element = Number of protons + number of neutrons

The atoms of same element having same atomic number but different mass numbers are called as isotopes.

#### Examples of isotopes

There are three isotopes of hydrogen having mass numbers 1, 2 and 3 resp having atomic number equal to 1. Isotopes of hydrogen are represented as 1H, 2H, 3H and are named as protium, deuterium, and tritium.

Ordinary hydrogen is known as protium. Isotopes of other elements or not having any special names. For example isotopes of chlorine are represented as 35Cl and 37 Cl. Therefore Chlorine is found to have two isotopes having same atomic number 17 but different mass numbers 35 and 37

### What are isobars ?

Some atoms of different elements have same mass number.

##### Calculation of number of neutrons, protons and electrons

Number of electrons = Number of protons = atomic number

As we know, Number of protons + Number of neutrons = mass number

Number of protons = Mass number – Number of neutrons

Also, Number of neutrons = Mass number – Atomic number

So, atoms of different elements having different atomic numbers but same mass numbers are called as isobars

#### Examples of isobars

So in all these species, 18Ar, 19K, 20Ca Argon Potassium and Calcium are having different atomic numbers 18,19, and 20 but having same mass number 40

You can watch all the related videos from  the structure of atom from the given playlist:

structure of atom

### What are isotones ?

Such atoms of different elements having same number of neutrons are called is isotones. For example carbon, nitrogen and oxygen differ in the atomic number as well as in mass number but are having same 8 neutrons.

#### Examples of isotones

3616S, 3717Cl, 3818Ar, 3919K, and 4020Ca are all isotones since they all contain 20 neutrons.

2. Consider the second example of isotone :

Chlorine-37 and Potassium-39

Chlorine (Cl) having atomic number 17

Number of protons  = 17

And No of neutrons = 37 – 17 = 20

Potassium (K) having atomic number 19

Number of protons = 19

So, Number of neutrons = 39- 19 = 20

Therefore, Cl and K are regarded as isotones

### What are isoelectronic species?

Ions of the different elements having same number of electrons by different nuclear charge or called as isoelectronic species.

N3–, O2–, F–, Ne, Na+, Mg2+, and Al3+ all are having same number of electrons. Author:

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