In a chemical reaction, 300 grams of reactant a are combined with 100 grams of reactant b. both a and  b react to completion. how much will the product weigh?

400 grams. Due to the law of consevation of mass. It states that mass quantitu must remain constant.

8

explanation:

each principal energy level above the first contains one s orbital and three p orbitals. a set of three p orbitals, called the p sublevel, can hold a maximum of six electrons. therefore, the second level can contain a maximum of eight electrons - that is, two in the s orbital and 6 in the three p orbitals.

mark brainliest and have a great day!