How to remember first 20 elements of the periodic table

1)each group 16 element has how many valence electrons? ( )4 ( )6 ( )8 ( )16 2)how many dots appear in the dot structure for calcium ion, ca2+? ( )zero ( )one ( )two ( )eight 3) which of the following atoms forms a cation to obtain an octet of outer shell electrons? ( )magnesium ( )oxygen ( )fluorine ( )helium 4) an al3+ ion contains 13 protons and 10 electrons. ( )true ( )false 5) valence and non-valence electrons are represented in lewis dot structures. ( )true ( )false

1. if you have a gas at 127 degrees c, what is it's absolute temperature (kelvin)? a. 200kb. 300kc. 400kd. 500k2. if you had a gas whose absolute temperature measured 45 k, what is that temperature in celsius? a. -228 cb. -300 cc. 125 cd. 112 c

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?