Lithium has one valence electron. bromine has seven valence electrons. how might they form a covalent bond?
a. bromine donates seven electron to lithium
b. bromine donates an electron to lithium
c. lithium donates seven electrons to bromine
d. lithium donates an electron to bromine

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.