Lithium and francium have similar properties because they
O
A. have the same number of electron shells
O
B. have the same number of electrons
o
C. have the same number of valence electrons
O
D. need the same number of electrons to fill their valence shells

Option C. have the same number of valence electrons

Explanation:

Lithium and francium belong to the same group because they both have the same number of valence electron. Having the same number of valence electron puts them in the same group. Group members possess similar properties. So Lithium and francium have similar properties because they have the same number of valence electron.

acid rain does not usually kill trees directly. instead, it is more likely to weaken the trees by damaging their leaves, limiting the nutrients available to them, or poisoning them with toxic substances slowly released from the soil. the main atmospheric pollutants that affect trees are nitrates and sulphates.