Question

Potassium (K) and copper (Cu) are both in period 4. They both have _____.

four electron shells
similar properties
the same number of electrons
the same number of protons

Answer 1

Potassium (K) and copper (Cu) are both in period 4. They both have Four electron shells.

Answer 2

Answer:

Similar properties

Explanation:

Potassium (K) has atomic number 19 which means its electron configuration (pattern of electrons in it's energy levels (electron shells)) is 2·8·8·1 while Copper (Cu) has atomic number 29 which means its electron configuration is 2·8·8·8·3 hence Potassium has 4 electron shells while Copper has 5

Potassium has 19 protons (from its atomic number) while Copper has 29 protons

The number of protons and electrons is usually the same (in an atom) (that's why atoms don't naturally have charges i.e they're usually neutral) so Potassium has about 19 electrons while Copper has about 29 electrons.

So similar properties automatically becomes your answer cuz the rest are wrong.