Matter Flashcards
Define Matter
Matter is anything that has MASS and OOCUPIES SPACE
What does Matter consist of
Matter consists of chemical elements in pure form and in combinations called molecules and compounds
What does an Elements properties depend on
An elements properties depends on the structure of its atoms
Each element consists of a certain type of atom - different from the atoms of any other type of elements
Differences between the atoms give the elements their different chemical properties
What are the 3 different forms an 1 type of atom can exist in?
- As a single atom
- As molecules
- The number of different combinations of atoms is vast
Define an Element
A pure substance that cannot be separated into ant other components by any physical or chemical means
Define Molecules and Compounds
A pure substance that can be separated into its elements by chemical means but not physical means
Physical Properties of a Solid
Molecules in fixed positions: ‘ordered structure’, a fixed volume and fixed shape
Molecules held together by intermolecular forces or chemical bonds but vibrating
Physical Properties of Liquids
Molecules still close together and still experiencing forces between the molecules but free to move, short range order only
Fixed volume but flows to fit shape of container
Physical Propertied of Gas
Molecules are far apart, no longer experiencing forced between the molecules
There is no order
Molecules moving fast and randomly
Flows and expands to fill and fit shape of container
What is a physical change?
In a physical change a substance is not converted into a new substance, it merely changes its physical state. Good examples are ice melting and water boiling
Chemical Change
A substance is converted into an entirely new substance. The molecules are broken up and reformed into the molecules of the new substance
Pure Substances
Have definite physical properties
Mixtures
Mixtures do not have definite physical properties
These are substances which can be separated into their components by physical means
Components of Mixtures
Mixtures can contain both elements, molecules and compounds
Homogenous Mixtures
Homogenous mixtures have the same composition throughout
They are said to contain only one PHASE
You cannot see boundaries under a microscope
Heterogenous Mixtures
Heterogenous mixtures do not have the same composition throughout.
Have more than one PHASE. Phase boundaries can be seen - may need a microscope to see it.
How do ions become positively and negatively charged
If an atom looses an electron it becomes a position ion
CATION
If it gains an electron it becomes a negative Ion
ANION
What is a free radical
A free radical is any molecular species that contains an unpaired electron and is capable of free existence
What is an Electrolyte
Molten ionic solids can conduct electricity
Ionic solids dissolved in water also conduct electricity
In both cases this is because the charged particles can move
we say they are electrolytes
many body fluids are electrolytes
