vers Assess It! Part 2 NE Use the vocabulary words from "Read It" to complete the following sentences. her As we look around space we find that most of it is composed of (4) of hydrogen. When the hydrogen combines with carbon it forms a (5) which is the basis for all living things. Combining different (6) together form different substances. A group of two or more atoms that are bonded together is called a (7) . And when the elements are combined in a specific way, or ratio, the substance is called a (8) (e. g. water).