What is the heat required to vaporize 650 grams of a liquid with a heat of vaporization of 723 joules/grams?
a. 0.90 j
b. 1.1 j
c. 73 j
d. 1,370 j
e. 470,000 j

they both have a y in them

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.