Elements, Compounds and Mixtures Flashcards
1
Q
Properties of metal
A
- shiny / lustrous
- mostly solids at rtp (except Mercury)
- high melting and boiling (except sodium, potassium, Mercury)
- ductile
- malleable
- sonorous
- good conductor of heat
- good conductor of electricity
2
Q
Metalloid properties
A
- shiny
- solid at rtp
- high melting and boiling point
- brittle (easily broken when hammered)
- moderate conductor of heat
- moderate conductor of electricity
3
Q
Non metal properties
A
- dull
- gases, volatile liquids or solids at rtp
- low melting and boiling point
- brittle if solid
- poor conductor of heat (except carbon in the form of graphite and diamond)
- poor conductor of electricity(except carbon in the form of graphite)
4
Q
Atoms
A
The smallest particles of an element that have the chemical properties of that element
5
Q
Molecules
A
A group of two or more atoms chemically combined
DIATOMIC
eg, iodine, chlorine, oxygen, nitrogen, hydrogen
POLYATOMIC
eg, sulfur (s8), phosphorous (P4), ozone (o3)
6
Q
Compound
A
A pure substance containing two or more elements that are chemically combined in a fixed ratio
7
Q
Properties of a compound
A
- a compound has different properties from its constituent elements
8
Q
Decomposition of compounds
A
- chemical processes such as thermal decomposition and electrolysis
9
Q
Mixture
A
- made up of two or more substances that are not chemically combined
- components are not fixed, can be present in any ratio
Eg, alloys
10
Q
MIXTURES VS COMPOUNDS
A
Separation:
- components of mixtures can be separated by physical processes such as magnetic separation, filtration or distillation
- compound can only be broken down by chemical processes
Properties
- mixture same as those of elements
- physical and chemical properties of a compound are different from its constituent elements
Energy change:
- no chemical reaction takes place when a mixture is formed
- chemical reaction takes place when a compound is formed, there is an energy change
Composition
- components of a mixture can be mixed in any proper ion
- elements in a compound are always combined in a fixed proportion
11
Q
Element
A
A pure substance that cannot be broken down into two or more simpler substances by chemical processes
