Cadium
Down a period, atomic radii decrease from left to right due to the increase in the number of protons and electrons across a period.
I would say A.evaporate because the water is getting absorbed.
You can say that if the volume of the gas is halved, the pressure is doubled.
The expression shows that pressure and volume are inversely proportional if temperature and amount of gas is held constant. This means that if volume goes down the pressure needs to go up. That also means that in order to maintain the K value, if pressure is doubled the volume needs to be halved and if the pressure is halved the volume needs to be doubled.
This relationship only works if we assume everything else (Temperature and moles of gas) to be constant.
