Across the period the size of an atom decreases and effective nuclear charge​

Atomic radius decreases across a period and increases down a group. Across a period, effective nuclear charge increases as electron shielding remains constant. Down a group, the number of energy levels (n) increases, so there is a greater distance between the nucleus and the outermost orbital.

Explanation:

- aluminum and copper chloride.

- the chloride ion to separate the aluminum from the oxygen so that the aluminum can react with the copper ions (and the water molecules).

answer

i think the answer is a) as air pressure in an area increases, the density of the gas particles in that area decreases.

hope it