First of all you have two of them. Convert all inches to feet. 1 foot = 12 inches 2 feet = 24 inches. 30 inches is a little harder 30/12 = 2.5 feet. Now you are ready to figure the problem Top A ===== Area = L * w L = 6 feet w = 2 feet A = 2 * 6 = 12 Square feet Top B ==== Area = 2.5 * 4 Area = 10 square Feet
Atomic radii INCREASES when going DOWN a group because of more energy levels and DECREASES going ACROSS a group because of the increasing positive charge of the nucleus pulling in on the electrons.