Matter is anything that has mass.All matter is acted upon by a force called gravity.Matter exist in three different states,SOLID,LIQUID and GAS.
SOLIDS
In a solid the molecules lie in a particular pattern.The molecules are close together and they vibrate about fixed positions.If the solid is heated, the total enery is divided among the molecules and makes them vibrate faster.Eventually they move so fast that they break loose from their fixed positions.The solid melt and becomes a liquid
LIQUIDS
The molecules of a liquid can move about within the liquid. They are in constant random motion and they also vibrate.If the liquid is heated,its molecules gain kinetic energy and move faster,until eventually molecules can escape from the surface.The liquid then vaporises and turn into gaseous state.
GASES
The molecules of a gas are also in constant motion but the molecules are comparatively far apart.They move at high speeds,colliding with one another and with the wall of the containing vessel and exert pressure on the walls of the container.The pressure of the gas is caused by the collision of the molecules with the walls of the container.
ATOMS AND MOLECULES
An atom is the smallest partice of an element which can have a seperate existence.
A molecule is the smallest particle of a substance which can have a seperate existence,whilst still keeping the properties of that substance.
OR
A molecule is a group of atoms of the same or different elements,joined in simple proportion.
DIFFUSION AND SURFACE TENSION(adhesion and cohesion)
Diffusion is tendency of a gas to mix intimately with one another and fill an empty space as a result of constant random motion of the molecules.The rate of diffusion depends on the densities of the gases:the lighter,or less dense the gas,the more rapidly it diffuses.
Surface tension is the tension or force acting parallel to the surface of the liquid.
Cohesion is the force of attraction between molecule of the same substance
Adhension is the force of attraction between molecules of different substances.
CAPILLARITY AND CRYSTAL
Capillarity is defined as the tendency of liquids to rise(fall)in a
narrow capillary tubes.
A crystal is a piece or solid matter in which atoms or molecules are arranged in a regularly repeating pattern or lattice.e.g sodium chloride(NACL).
AMORPHOUS SUBSTANCE
Amorphous substance is a solid that lack the definite or oderly arrangement of atoms e.glass and plastic.
ELASTICITY
A body is said to be elastic if it regians its original shape and size after undergoing a stretching or compression.
HOOKE'S LAW
State that provided the elastic limit is not exceeded,the extension in an elastic material is proportional to the load or applied force.
F=ke
where f=applied force or load
k=force constant or stiffness
e=extension.
E=½ke²=½fe
where E=workdone in extending a spring.
YOUNG MODULUS
Young modulus is therefore defined as
E = stress/strain
E = F/A=E/L
stress =F/A
F=force
A=surface area
strain = E/L
strain =extension/original length
