Unit four: Matter

• What is matter• Properties of matter• States of matter

Chemistry & Matter

• What is Chemistry?

• “Chemistry is the study of the structure, function, and composition of matter”

What is Matter?

• Matter is anything that has mass and takes up space.

What is Matter?

Identify which of the following would be considered matter:

• a computer • microwaves • paper • iron • heat

• ice cream

• time • sound • wood • Mars • sand • sunlight• a rock • the Sun • energy • a spider

• a tree • paint • snow • memories • clouds • a sandwich • a fingernail • thoughts • gravity

What is Matter?Identify which of the following would be considered matter:

• a computer • microwaves • paper • iron • heat • ice cream • time • sound • wood • Mars • sand • Sunlight

• a rock • the Sun • energy • a spider • a tree • paint • snow • memories • clouds • a sandwich • a fingernail • thoughts • gravity

Matter = 16 , non-matter = 9

Other definitions:What are elements?• An element is a pure substance that is made

up of only one kind of atom.What are atoms?• Atoms are the smallest unit of an element

that maintains the identity of that element.What are compounds?• A compound is a substance made up of two or

more elements that are chemically bonded.

Know your Elements!

1. Elements are the simplest form of matter.2. Elements are the building blocks of all

substances and cannot be easily divided into smaller subunits by ordinary chemical processes.

3. Elements are organized by atomic number on the periodic table.

4. Elements are identified by their symbols.

Elements & Symbols

• The symbol of an element is often taken from its name. • The first letter is always capitalized.

• If an element starts with the same letter as another element, sometime the first two letters are used.

• The second letter is always lowercase.

• Some elements have symbols that don’t match the name of the element because their name comes from another language.

• element song

Elements & Symbols

Hydrogen

Carbon

Sodium

Nitrogen

Oxygen

Fluorine

Helium

Lead

Chlorine

Magnesium

H

C

Na

N

O

F

He

Pb

Cl

Mg

Elements & SymbolsPotassium

Sulfur

Copper

Silver

Gold

Iron

Nickel

Zinc

Aluminum

Calcium

K

S

Cu

Ag

Au

Fe

Ni

Zn

Al

Ca

What are Compounds?1. Compounds are substances that are made up of two or more types of

atoms.

2. Atoms in a compound are held together by chemical bonds.

3. Compounds can be broken into simpler substance through chemical processes.

4. Compounds are described using chemical formulas. The symbols tell what element and the subscript tells us how many.

5. Some examples of common compounds include:Water – H2O , Carbon Dioxide CO2, Sugar – C12H22O11

Common compounds

Name Formula

Water H2O

Carbon Dioxide CO2

Sugar C12H22O11

Sodium Chloride NaCl

Ammonia NH3

Hydrogen Peroxide H2O2

Methane CH4

Properties of Matter

Properties of matter can be divided into two categories:

A physical property can be observed or measured without changing the identity of the substance.

A chemical property describes the ability of a substance to undergo changes and turn into another substance. It changes the chemical identity of the substance.

Some examples of Physical Properties:

• Melting point• Boiling point• Brittleness• Color• Solubility (can it dissolve?)

Some examples of Chemical Properties:

• Reactive• Flammable• Explosive• Toxicity

Changes in Matter

Changes in matter can be divided into two categories:

A physical change is a change in a substance that does not change the identity of the substance.

A chemical change is a change in which one or more substances are converted into different substances with a new chemical identity.

A chemical change is also called a chemical reaction.

States of Matter

The three states of matter include:Solid: Liquid: Gas

States of matter interactive

State Volume Shape

Solid definite definite

Liquid definite indefinite

Gas indefinite indefinite

States of matterSolid

LiquidGas

Phase Change & Energy

Background to states of matter and phase changes:.

1. Particles of matter are in constant motion.

2. Energy in motion is called kinetic energy.

3. Temperature describes the kinetic energy of matter.

example of states of matter and energy

Phase Change & Energy

As temperature increases : Kinetic energy ____Particles moves ____

As temperature decreases : Kinetic energy ____Particles moves ____

Energy and phase change

• When Heated:

Solid liquid gas• When Cooled:

Gas liquid solids

A change in state (phase change) is a physical change.

Energy & phase change