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C. Isotopes, Isobars, and Isotones

Isotopes
Atoms that have the same atomic number but different mass numbers are called isotopes.

Take a look at the three isotopes of the element hydrogen (Z = 1) : , , and )

Isobars

Atoms from different elements that have

different atomic number (Z) can have the same

mass number (A). Such atoms are called

isobars. Examples of isobars are hydrogen atom

and helium atom .

Isotones

Atoms from different elements with different

atomic numbers (Z) can have the same number

of neutrons (n). Such atoms are called isotones.

For examples, hydrogen atom and helium

atom .

Self - Practice

From these six pairs of atoms, determine which are isotopes, isobars, and isotones.

a. and d. and

b. and e. and

c. and f. and

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