CScope Unit 3 Vocabulary and Key Understanding 1. Element- a pure chemical substance made of only one kind of atom 2. Pure Substance -a material with a definite (certain, fixed) chemical composition 3. Chemical Symbol -Notation of one or two letters derived from the scientific names of the chemical elements. 4. Circle Graph- A graph comparing the parts of something to the whole thing. 5. Compound- two or more elements bonded (joined) together to create something new. Key Understanding: 1. An element is a pure substance that cannot be broken down into simpler substances. 2. A small number of elements make up the largest portion of solid Earth, living matter, oceans, and atmosphere. 3. The atoms of an element do not have the same properties as the element. For example the atoms of copper are not orange and shiny.