1.1 Atoms, elements and compounds Flashcards
(21 cards)
Atom
The smallest part of an element that can exist.
What do atoms make up?
All substances
How many elements are there?
Around 100
Where are elements found?
Periodic table
Compounds
Two or more elements chemically bonded together in fixed proportions.
Ionic compounds
Metal and non metal bonds.
Mixture
Two or more elements not chemically bonded together
How are mixtures separated?
Physical processes.
How are compounds separated?
Chemical reactions.
Types of physical processes of separation.
- Filtration
- Crystallisation
- Simple distillation
- Fractional distillation
- Chromatography
Filtration
Purpose: separate insoluble solids from solution.
Equipment: filter paper, funnel, flask
Process: solution is poured into filter paper - solvent is left in funnel and residue is left in filter paper.
Crystallisation
Purpose: separate solvent from solution.
Equipment: evaporating basin, bunsen burner
Process: solution is gently heated in evaporating basin and cooled - crystals form, solute evaporates.
Distillation
Purpose: separate solutes in solution with different boiling points
Equipment: distillation set up.
Process: solution is heated - solvent with highest boiling point dissolves last and solutes end up in separate beakers.
Chromatography
Purpose: separate mixture of dye due to different solubilities.
Equipment: chromatography paper, solute.
Process: solute travels up paper and ink also travels up according to solubility.
Rf value
Rf value = distance travelled by solute / distance travelled by solvent.
Location of subatomic particles
- Proton: nucleus
- Neutron: nucleus
- Electron: energy shells
Relative charge of subatomic particles
- Proton: +1
- Neutron: 0
- Electron: -1
Relative mass of subatomic particles
- Proton: 1
- Neutron: 1
- Electron: very small
Size of atom
1 x 10-10m (0.1nm)
Size of nucleus of atom
1 x 10-14m
