In which direction on the periodic table, horizontal or vertical, are elements with similar chemical properties aligned? what are families of elements with similar chemical properties called?

When svante arrhenius first proposed his acid-base theory, he was a doctoral candidate. his professors thought his ideas were unfounded. within a decade, the arrhenius theory of acid-base was widely accepted and praised within the scientific world. arrhenius defined acids as compounds having ionizable hydrogen and bases as compounds with ionizable a) barium. b) hydronium. c) hydroxide. d) oxygen.

If 90.0 grams of ethane reacted with excess chlorine,how many grams of dicarbon hexachloride would form

If cos x =sin(20 + x) and 0 < x < 90, the value of x is > 3 , 35 , 350answer is 35, free 50 points