Introduction to matter

What it mass

• Mass- the amount of matter that an object has

• Weight-the force of gravity on the mass of an

object

• Is mass the same everywhere?

Matter

• What is matter?Matter is a term for the substance of

which all physical objects are made.

• Matter is made up of very small particles called atoms.

• Matter is found in three different phasesSolidLiquidGas

Liquid

Gas

Solid

Properties of a solid

• Solids-A substance in a solid phase is relatively rigid,

has a definite volume and shape.

The atoms or molecules that comprise a solid are packed close together and are not compressible.

• A solids atoms do move. However, this movement is very small and very rapid, and cannot be observed under ordinary conditions

Properties of a liquid• Liquids have a definite volume, but are able to

change their shape by flowing.

• Liquids are similar to solids in that the particles touch. However the particles are able to move around.

• Since particles are able to touch the densities of liquid will be close to that of a solid.

• Since the liquid molecules can move they will take the shape of their container.

Properties of a gas

• Gases have no definite volume or shape. If unconstrained gases will spread out indefinitely. If confined they will take the shape of their container.

• Each of the particles are well separated resulting in a very low density.

Density

• Density-is defined as its mass per unit volume.

The formula for density is given as

V

mD

• Mass-The amount of matter and object has. It

is often referred to the weight of an object. Often expressed by

grams = g

• Volume-is how much three-dimensional space a

substance or shape occupies or contains. Often expressed by

mL or cm3

Example problem

• A 43 gram block of wood has a volume of 30 cm3 what is the density of the block?

• If a block has the mass of 15 grams and a density of 2 grams/cm3 what is its volume?