Answer:
The answer are: a. the law of definite composition; b. the law of conservation of mass; d. the law of multiple proportions
Explanation:
Dalton based his atomic theory on two laws: the law of conservation of mass and the law of definite composition.
The law of conservation of mass says that in a closed system, matter is not created or destroyed. For example, if there is a chemical reaction, the amount of each element of that reaction is the same in the reagents and in the products. While the law of defined composition says that a pure compound will have the same proportion of the elements that make it up. An example, salt, which has a chemical formula NaCl, has the same proportion of sodium and chlorine.
The law of multiple proportions, when two elements come together in different proportions to create different compounds, this means that their atoms come together in different numerical relationships. For example, if an atom of an element A joins with two atoms of element B, the weight ratio of the quantities that bind are in a ratio of 1: 2.