Question

Write an equation representing for each of the following : (a) The change of a magnesium atom to a magnesium ion (b) the change of a bromine atom to a bromide ion

Answer 1

(a) The change of a magnesium atom to a magnesium ion

We could represent this as half - reaction:

Mg has 2 electrons in its outer shell. To become an ion, it must lose those 2 electrons:

Mg => Mg+2 + 2e-

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(b) The change of a bromine atom to a bromide ion

Bromine has 7 electrons on its outer shell. It must gain 1 electron to become an ion

Br + 1e- => Br-