Revision Of Matter And Classification Flashcards
Brittle def
How easy it is to break
Malleable
The material can be bent and hammered into sheets
Ductile
The material can be drawn into wire
Thermal conductivity
The material can conduct heat
Electrical conductivity
Material conducts electricity
Lustre
Shine that material has
Magnetic
Material can be attracted by a magnet
Density
Mass of material per unit volume
Sonorous
Material emits ringing sound when struck
Melting point
Temperature at which material changes from solid to liquid
Boiling point
Temperature at which material changes from liquid to gas
Types of mixtures
Homogeneous and heterogeneous
Mixture
Two or more substances combined in which the substances retain their own properties
•Substances present in ratio
Homogeneous mixture
- Mixture with the same composition throughout
* Usually consists of substances in the same phase
Examples of homogenous mixtures
- Saline solution
- Metal alloy
- Water and sugar without crystals at the bottom
- Air
Heterogenous mixture
- A mixture without a uniform composition
* Any combination of molecules that do not dissolve in one another
Examples of heterogeneous mixtures
- Sand and water
- Oil and water
- Sugar and water with crystals at the bottom
- Salt water
Suspension
When a substance does not dissolve but is merely dispersed throughout the solvent or water
Emulsion
When you take two or more substances that are immiscible and attempt to mix them
Immiscible
When two liquids do not mix
Emulsifiers
Substances added to emulsions to stop them from separating into layers
Example of emulsion
Mayonnaise as a result of egg yolk in oil
Checks for boiling point
- By using boiling points or melting points as a guide
* Chromatography
Properties of mixtures
- Impure substance
- Physical combination of two or more substances
- Separated by physical means
- Substances making up mixtures retain their properties
Element properties
- Pure substance
- Has one atom
- Can’t be separated
- Has own unique properties
Compound properties
- Pure substance
- Chemical combination of two or more elements
- Made by elements in fixed ratios
- Can be separated by chemical means
- Properties of compounds are different from the properties of elements
Solid phase
- Strong forces called crystal lattice
- Vibrate in fixed position
- Has shape
- Has volume
- Particles are close to each other
Liquid phase
- Weaker forces than solid
- Particles move over each other
- Takes shape of container
- Has own volume
- Particles are close together not compressible
Gas phase
- No forces
- Free to move
- No shape, fills container
- Has volume of container
- Compressible particles,far apart
Freezing point
Temperature at which a liquid changes to a solid
What happens when a gas vools?
Condenses
Evaporation
When the molecules near the surface with more kinetic energy overcome forces of attraction and escape the liquid and turn into water vapour
What happens after evaporation
The less energetic particles are left, causing remaining liquid to drop
Differences between evaporation and boiling
- Evaporation happens at any temperature and boiling happens at a specific temperature
- Evaporation takes place at the surface only but boiling throughout the liquid
- Boiling takes place when vapour in bubbles is equal to atmospheric pressure.
Sublimation
When a substance goes straight from being a solid to a gas
What happens to molecules of the solid phase when heated?
- They vibrate more energetically, increasing their average kinetic energy and thus the temperature rises
- While these molecules vibrate forces of attraction build up and therefore when they get close to each other there are forces of repulsion between them
