Chemistry
How is Matter Classified?
Name:__________________
Date:___________________
Objective: Distinguish between atoms, elements, molecules, and compounds.
1. When is a sample of matter considered a pure substance?
It is a pure substance when it is made up of only one kind of atom or molecule.
2. How does an atom differ from an element?
Atoms are the smallest unit of which elements are made.
3. How does an atom differ from a molecule? Give examples.
Atom is the smallest unit of element.
Molecule consists of one or more atoms joined together chemically.
4. What is an allotrope? Give an example.
An allotrope is one of a number of different molecular forms of an element in the
same state, e.g. O2, O3
5. What is the difference between an element and a compound? Give examples.
An element is a pure substance that contains only one kind of atom, e.g. Ag, H2
A compound is a pure substance of more than one kind of atoms, e.g. CO2, CaO
6. What is the difference between a molecule and a compound? Give examples.
A molecule consists of one or more atoms joined together chemically, e.g. Cu, H2
A compound is a pure substance of more than one kind of atoms, e.g. CO2, NaOH
All compounds are molecules, but not all molecules are compounds.