Everything is made out of MATTER.
MATTER can exist in three physical states: SOLID, LIQUID or GAS.
All MATTER has mass (or weight) and volume (occupies space).
MATTER can undergo a CHANGE OF STATE
when the physical state changes but the matter or substance stays the same.
(Solid ice melts into liquid water;
liquid water evaporates into gaseous water vapour;
water vapour condenses into liquid water;
and liquid water solidifies into solid ice.)
MATTER can also undergo a CHEMICAL REACTION
when the substance permanently changes into a different substance(s).
(Oxidation and Conbustion are examples of chemical reactions.)
MATERIALS are substances we use for making things.
Two classifications of materials are: NATURAL or MAN-MADE.
We choose materials that have useful properties, such as:
STRONG and RESISTANT (steel, concrete)
FLEXIBLE (leather, paper)
ELASTIC (rubber, some plastics)
TRANSPARENT (glass, some plastics)
LIGHT and RESISTANT (aluminium)
FRAGILE (ceramics)
