Structure 1.1 Flashcards
What are elements?
Primary constituents of matter, they cannot be chemically broken down into simpler substances
Chemical Element
A neutral substance that cannot be chemically broken down into simpler substances. It consists of only atoms that contain the same number of protons.
Compound
A pure substance occurring when two or more chemical elements are chemically bonded together. It has different properties from its component elements.
Solids
Occupy a fixed space and volume. Particles held closely together in a lattice.
Liquids
Fixed volumer that takes the shape of its container. Particles are close together but move with random motion.
Gases
Completely fill their container particles are widely spaced and move with rapid random motion.
Heat
A measure of the total amount of energy in a given amount of substance. Depends on the amount of substance present. Measured in Joules (J)
Temperature
The measure of the average kinetic energy or ‘hotness’ of a substance. Independent of the amount of substance present. Measured in Kelvin.
What happens at 0K?
All motion has stopped. Absolute zero
Litre to Meter conversions
mL=cm^3
L=dm^3
When do liquids boil?
When their vapour pressure equals atmospheric pressure. Lowering/raising will lower/raise the boiling point.
Melting
Changing from a solid to a liquid
Freezing
Changing from a liquid to a solid
Vaporisation
Changing from a liquid to a gas
Evaporation
Changing from a liquid to a gas below the boiling point
Boiling
Changing from a liquid to a gas when the vapour pressure equals the external pressure
Condensation
Changing from a gas to a liquid
Sublimation
Changing from a solid to a gas without going through a liquid state