All Flashcards
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?
- 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.