What category of elements is characterized by the filling of d orbitals? Halogens
Alkali Metals
Transition Metals
Alkaline Earth Metals

Explanation:

Transition Metals are characterized by the filling of d orbitals?

the old alchemists made significant contributions to science even though there starting premises were off a bit. their conclusions after failure would steer them into better directions for investigation. science is no more than close observation and the initial mistakes result in rethinking and retrying experiments.

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.