# Question #e2cd6

##### 1 Answer

Three ways of expressing it:

+1 (relative charge)

Or *+e* , where *e* is the elementary charge.

Or

#### Explanation:

Potassium atoms lose one electron when they form an ion, so it has one more proton than electron giving it an overall positive charge equal to the charge on a proton. Protons and electrons have equal charges but opposite sign.

So for simplicity we can say that potassium forms a +1 ion, indicating that it has 1 more proton than the total number of electrons.

In atomic terms charges only change in multiples of the elementary charge. The elementary charge, *e* is the magnitude of the charge on an electron or proton. Atoms can only lose or gain whole numbers of electrons so the overal charge can be expressed in terms of *e*. For a potassium ion it is *+e*.

The value of *e* in coulombs is

All elements in group 1 of the periodic table form a positive ion with the same magnitude of charge as potassium.