# Chapter 2 Notes - Richmond Heights Schools

```Chemistry is the study of
Matter and the transformation
It can undergo.
Matter is anything that
Occupies space.
It is the stuff that makes up
All things.
An element is a substance that cannot
Be separated or broken down into
Simpler substances by chemical means
An atom is the smallest unit of an element
That maintains the properties of
That element.
A compound is a substance made from
Atoms of two or more different
Elements that are chemically combined.
A molecule is the smallest unit of a
Substance that keeps all of the
Physical and chemical properties
Of that substance.
A pure substance is a sample of matter,
Either a single element or a
Single compound, that has definite
Chemical and physical properties.
A mixture is a combination of two or
More substances that are NOT
Chemically combined.
A mixture where everything is evenly
Distributed is called homogeneous.
A mixture that is NOT evenly distributed
Is called a heterogeneous mixture.
A chemical formula is a combination
Of chemical symbols and numbers
To represent a substance.
Some properties of matter, such as
Color and shape, are called
Physical properties.
Some physical properties are:
Mass, volume and Density.
An easily observed physical property
Is its state: solid, liquid or gas.
Melting point is the temperature and
Pressure at which a solid
Becomes a liquid.
Boiling point is the temperature
And pressure at which a liquid
Becomes a gas.
Solids, liquids and
gases are matter, so
they all have density.
 Density is a property of material
independent of quantity or shape.
10.1 Density
 The units used for
density depend on
whether the
substance is solid
or liquid.
 For liquids use
units of grams
per milliliter
(g/mL)
 For solids use
density in units of
g/cm3 or kg/m3.
10.1 Determining Density

To find the density of a
material, you need to know
the mass and volume of a
solid sample of the
material.
1. Mass is measured with a
balance or scale.
2. Use the displacement
method or calculate the
volume.
Solving Problems
A solid wax candle has a volume of 1,700
mL.
The candle has a mass of 1,500 g.
What is the density of the candle?
Solution:
&sect; 1,500 g &divide; 1,700 mL = 0.8823529 g/mL
Chemical property is a property of
Matter that describes a substance’s
Ability to participate is chemical reactions.
Reactivity is the ability of a substance
To combine chemically with
Another substance.
Flammability is the ability of a
Substance to react in the presence
Of oxygen and burn when
Exposed to a flame.
There are 2 kinds of changes for matter
Chemical
&amp;
Physical

A physical change is any change in
the size, shape, or phase of matter in
which the identity of a substance
does not change.

For example, when water is frozen, it
changes from a liquid to a solid.

Any change that transforms
one substance into a different
substance is called a chemical
change.
Iron reacts with oxygen
to form iron oxide.
Ex. If you leave a nail
outside, it rusts.
```