Movement of electrons about a central nucleus is a concept by whom?

Bohr.

Explanation:

In 1913, N.Bohr proposed an atomic model for atom. He proposed that in an atom there is a central nucleus and electrons move around this center in a fixed path known as shell.

The shells or path have a fixed size and energy. The electrons do not lose energy during this movement.

There is possibility of energy change (emit or absorb) in an electron if they move from one shell to another.

hi,

the capital city of australia is canberra.

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.