How many valence electrons does hydrogen need to have a full first shell?

Which of the following substances is the most soluble in water? a. sodium chloride b. methane c. bromine d. carbon

How many grams of sodium chloride are in 250ml of a 2.5m naci solution

Four statements about the development of the atomic model are shown below. a: electrons have wavelike properties. b: atoms have small, negatively charged particles. c. the center of an atom is a small, dense nucleus. d: atoms are hard, indivisible spheres. which order of statements represents the historical development of the atomic model? c-d-a-b c-d-b-a d— в-а — с d-b-c-a