States of matter Flashcards
Gas
Particles are far apart, occasionally bumping into each other. Greatest energy.
Takes shape of container, particles move in all directions. Can be compressed
Solid
Particles very close, low energy. vibrate around a fixed position, Regular pattern. Cannot be compressed.
Liquid
Greater energy, Close together, randomly arranged. Move around each other. Take shape of container. Cannot be compressed
How does a substance change state?
Energy must be transferred through heating, allowing the particles to gain energy. When the particles have enough energy the bonds that are holding them together break. This allows solids to become liquids, liquids to become gas etc
Sublimation
Conversion between solid and gas. Skips liquid
Ion Formation
Atoms lose or gain electrons to form a full outer shell. Non metals gain electrons, metals lose electrons
Ionic compound
Giant structure of ions. Regular repeating pattern called ionic lattice. Oppositely charged ions attract and form a regular pattern
Ionic bonding
Held together by strong electrostatic forces of attraction. Occurs when a electron leaves one atom to complete another and vice versa.
Covalent bonds
Atoms share a pair of electrons. occurs in most non metal elements, and in compounds formed between non metals.
Simple molecule properties
Low melting points and boiling points.
Intermolecular forces
Weaker forces, inbetween atoms. These are what break when a substance boils or melts.
When can a substance conduct electricity
If it contains charged particles and these particles are free to move from place to place eg: Dissociated electrons in metals
Metallic bonding
Delocalized outer shells, regular pattern. Giant structures. They SHARE Delocalized electrons
Properties of metals
Good electrical conductors as delocalised electrons carry charge through metal. Good thermal conductors. High melting and boiling points - Metallic bonding is very strong.
Define Alloy
Mixture of 2 or more elements.
