CScope Unit 4 Vocabulary and Key Understandings
1. Compound: Made from two or more elements that are chemically
combined and cannot be separated by physical means into other
substances
2. Mixture: A combination of more than one substance, but it does not
create a new substance and it can be separated
3. Chemical Formula or Chemical Symbol -Notation of one or two
letters derived from the scientific names of the chemical elements.
4. Element- a pure chemical substance made of only one kind of atom
5. Subscript: the number written below and behind a chemical symbol
which tells the number of atoms of that element
6. Molecule: the smallest physical unit of an element or compound,
consisting of one or more like atoms in an element and two or more
different atoms in a compound.
7. Precipitate: The solid that is formed as a result of a chemical
reaction
8. Signs (evidence) of a chemical change:
a. Production of a gas
i. Bubbles
ii. Odor
b. Change in temperature
c. Production of a precipitate
d. Color change
Key Understandings
1. A Compound is a substance made by chemically combining two or
more elements
2. The formation of a new substance may be identified by the evidence
of a chemical change:
a. Production of a gas
b. Change in temperature
c. Production of a precipitate
d. Color change
3. The new substance formed in a chemical change will have a different
chemical symbol