2NH₃(g) + CO₂(g) → CO(NH₂)₂(s) + H₂O(l)
is the balanced equation for the synthesis of urea.
The water from the lake must first evaporate from the liquid state to the gaseous state and then condense in the air to form vapors.
The water molecules absorb energy while evaporating and release it when condensing. Their motion gets faster when they are evaporating and slows back down upon condensation.
Metals of Group 1 donate 1 electron from its ns orbital to form ionic bond, where n is the no. of its outermost shell.
Metals of Group 2<span> donate 2 electrons from its ns orbital to form ionic bond, where n is the no. </span>of its <span>outermost shell. </span>