Unit 2: Properties & Changes of

Matter

Bellwork

List 2 qualitative and 2 quantitative observations about this picture.

Lesson 1: LEARNING OBJECTIVES:

Identify the states of matter

Compare the physical and chemical properties of matter

Differentiate between mass and weight

Describe how matter is measured to calculate mass, volume and density

States of Matter

Matter is anything that has mass and takes up space.

The 4 states of matter are:▪ Solid▪ Liquid ▪ Gas▪ Plasma

Shape & Volume of Matter

Type of Matter

Shape & volume How are Atoms moving?

Attractive force between atoms

Solid Definite shape and volume

vibrating Strong – holding them together

Liquid Definite volume but no definite shape

Sliding past each other

Weaker force than solids

Gas No definite shape and volume

Atoms moving fast and free

Very weak attractive force

Plasma(Not in book)

No definite shape or volume

Atoms moving fast and free with an electrical charge

Very weak attractive force

What do the particles (atoms) look like in each state of matter?

Practice with matter and energy1. What do you do to change a solid

to a liquid?

2. What do you do to change a gas to a solid?

3. In which state of matter are the particles always moving?

Practice Answers

1. What do you do to change a solid to a liquid?

You add energy2. What do you do to change a gas to

a solid? You take energy away3. In which state of matter are the

particles always moving? ALL OF THEM

Physical Properties of Matter

1. Mass and Weight: ▪ Mass- amount of matter in

an object▪ Weight –mass X the

gravitational pull on an object

2. Volume: the amount of space an object takes up

L x w x h = cm3

OR

Displacement- Used to

measure the volume of

irregular shaped objects

OR

For Liquids

3. Density: the amount of matter in an object divided by the volume. D = m/v

▪ Density of water = 1g/cm3

If density of a substance is less than 1, it will float

If density of a substance is greater than 1, it will sink

▪ Temperature affects density: Temp. increases; density decrease Temp. decreases; density increases

▪ Salinity affects density: Salinity increases; density increases Salinity decreases; density decreases

Practice

1. How do you measure the volume of a rectangular object?

2. How do you measure the mass of an object?

3. Why is our weight different on the Moon than here on Earth?

Practice answers

1. How do you measure the volume of a rectangular object? Length X width X height

2. How do you measure the mass of an object? using a balance scale and measured in

grams

3. Why is our weight different on the Moon than here on Earth? Weight is dependent on the gravitational pull and the Moon has less gravity so we have less weight on the Moon.

4. Conductivity: the ability of an object or substance to conduct electricity.

5. Boiling Point: the temperature at which the liquid changes to gas (Water = 100 degrees Celsius or 212 degrees Fahrenheit)

6. Melting Point: the temperature at which a solid becomes a liquid (Water = 0 degrees Celsius or 32 degrees Fahrenheit)

7. Solubility: the ability of an object to dissolve in another

▪ Solute- the substance being dissolved

▪ Solvent- the substance in which the solute is being dissolved in.

Water is considered a universal solvent.

8. Magnetism: the ability of an object to attract a magnetic force

Practice

1. In the ocean, water is the _____________ and salt is the _____________.

2. The ability of an object to dissolve in another substance is called _____________________.

3. The temperature shown when a liquid changes to a gas is called the ________________.

Practice answers

1. In the ocean water is the _solvent_ and salt (Sodium Na) is the _solute____.

2. The physical property of matter that ability of an object to dissolve in another substance is _solubility____.

3. The physical property of matter that is when a liquid changes to a gas is __boiling point____.

Identifying Matter Using Physical Properties.

Density and Melting Point are good properties for identifying unknown substances because they do not depend on the size of the sample( the amount of the material).

Chemical Properties of Matter

Chemical property: the ability or inability of a substance to combine with or change into one or more new substances

Examples: Flammability: the ability of a type of substance to

burn easily. Most flammable = Hydrogen (H) gas

Reactivity : the ability of a type of substance to react with another substance. Most likely to Rust (react with oxygen) = Metals with Iron (Fe)

Written response

What happens to the density of an object when you cut it in half?

Give a situation where you would need to know whether a substance or object is reactive or flammable.

Lesson 2: LEARNING OBJECTIVES:

Identify the types of changes of matter – physical and chemical

Compare the signs of physical and chemical changes of matter

Describe how mass is conserved when a chemical reaction occurs (Law of Conservation of Mass)

Physical Changes of Matter

A change in the size, shape, form, or state of matter that does NOT change the matter’s identity is called a physical change.

Examples: melting ice ripping paper cutting wood erosion of a boulder

Dissolving and Changing States Because the chemical

properties of the substances in dissolving and changing and change of state stays the same, they are considered to be physical changes.

Chemical Changes A chemical change is a change in matter in

which the substances that make up the matter change into another substance with different chemical properties

Signs of a Chemical Change

Formation of Gas Explosion

Formation of precipitate Odor change

Color change

Energy and Chemical Change

The Law of Conservation of Energy : energy cannot be created or destroyed, but it can be transformed

Some chemical changes release thermal, light, and sound energy.(Exothermic Reactions)

ex: Burning

Some chemical changes need thermal energy for them to occur. (Endothermic Reactions)

ex: photosynthesis

Law of Conservation of Mass

Law states that the total mass before a chemical reaction is the same as the total mass after the chemical reaction.