What is matter?
Anything that has mass and takes up space.
What is a pure substance?
Composed of a single type of atom or molecule with consistent composition throughout.
What is an element?
A substance made up of only one type of atom.
What is a compound?
A substance made up of two or more different elements chemically bonded in a fixed ratio.
What is a formula unit?
Represents the lowest whole-number ratio of atoms in a compound.
What is the law of definite proportions?
A chemical compound always contains the same elements in the same proportions by mass, regardless of the source or sample size.
What is an empirical formula?
The simplest whole-number ratio of atoms in a compound.
What are the steps to determine the empirical formula from percent composition?
1. Percent to grams. 2. Grams to moles. 3. Divide by the smallest mole value. 4. Multiply to get a whole number ratio.
What are the differences between solids, liquids, and gases?
Solids: Fixed shape and volume, strong bonds. Liquids: Fixed volume, no fixed shape, weaker bonds. Gases: No fixed shape or volume, very weak bonds.
What are the differences between elements and compounds?
Elements: Made up of only one type of atom. Compounds: Made up of two or more different elements chemically bonded.
What is the difference between molecular and empirical formula?
Molecular Formula: Shows the actual number of atoms of each element in a molecule. Empirical Formula: Shows the simplest whole number ratio of atoms of each element in a compound.
