The ATOM

The atom consists of three basic parts:

The 3 parts:

Proton: + charge( +1)

Neutron: no charge (0)

Electron: - charge (-1)

• The proton and neutron make up the middle of the atom, called the nucleus.

• The electrons orbit the nucleus.

Two or more atoms bonded together make a molecule

A water molecule consists of two Hydrogen atoms bonded to one Oxygen atom (it’s the “Mickey Mouse” molecule)

•Everything in the universe is made of atoms/molecules.

•They can be very complex!

• This is a molecular model of a supramolecular complex of phenylcarborane with two b-cyclodextrin molecules, a drug being tested to treat brain tumors.

Properties of Matter

Lesson 1-5 Notes

What is Matter?

• Matter is all the substances that make up the universe. All matter has mass and volume.

– Mass is the amount of matter(stuff) in an object and is measured in milligrams (mg), grams (g) and kilograms (kg). We use an electronic scale in our class to find mass.

– Volume is a measure of space taken up by matter and is measured in cubic centimeters (cm³) for a solid and gas. Milliliters (ml) is used for a liquid

How do you find the Volume of a box –shaped object?

• The volume of a regular shaped object such as a rectangular box can be found by multiplying the measurements of length, width, and height.

• For example: to find the volume of the object below you would

multiply 3 cm x 3 cm x 12 cm, which equals 108 cm3

3 cm3 cm

12

cm

How do you find the Volume of an irregular shaped object?

• To find the volume of an irregular shaped object: 1. Fill a container (a graduated cylinder) with enough water to

submerge the object 2. Measure the volume of the water 3. Place the object in the water 4. Measure the increase of the volume of the water by subtracting the

original volume of water by the new volume of water. 5. The increase in volume is the volume of the object.

• Final Vol – Initial Vol= Vol of Object• (9ml – 7ml = 2ml = 2cm3 for a solid object)

• Called the Water Displacement method

How do you calculate Density?

• Density is the measurement of how much mass of a substance is contained in a given volume.

• Basically, density is a measurement of how tightly matter is compacted together.

• Density can be calculated by comparing mass and volume, by using the following formula: density equals mass divided by volume D = M/ V D= Solids =g/cm³ D= liquids = g/ml

Sample Density Problem

• A small block of wood floats on water. It has a volume of 25 cubic centimeters and a mass of 20 grams. What is the density of the wood? Volume = 25 cubic centimeters Mass = 20 grams

CALCULATE DENSITY: D = m / v D = 20 g/ 25 cm³ D = 0.8 g / cm³

Why do substances with different densities sink or float in liquids?

• An object that is more dense than the fluid in which it is immersed sinks.

• An object that is less dense than the fluid in which it is immersed floats to the surface.

• Lastly, if the density of an object is equal to the density of the fluid in which it is immersed, the object neither rises nor sinks in the fluid, it floats at a constant level.

• You can use Density to predict whether an object will sink or float when placed in a liquid

• Note: The density of water is 1.00 g/ml = 1 g/cm3

How does the differing densities of oil and water allow oil to float?

• Oil is less dense than water, it will float.

Don’t mix – immiscible!

Why does ice float in water?

• Ice is less dense than water and therefore floats.

• Ice is less dense because as it freezes its volume increases.

• Since its mass is constant, an increase in volume results in a decrease in density.

How does temperature affect density?

• When a solid, liquid or gas are heated, the molecules move faster, bump into each other, and spread apart. Since the molecules are more spread apart, they take up more space. The volume is increased and the substance becomes less dense.

• The opposite occurs when a liquid or gas is cooled. The molecules move more slowly and take up less space. The substance becomes ______________

• http://mutuslab.cs.uwindsor.ca/schurko/animations/waterphases/status_water.htm

Chemical Changes• Chemical changes are changes substances

undergo when they become new or different substances.

Physical Changes• Physical changes occur when objects

undergo a change that does not change their chemical nature.

• During physical changes a substance can be During physical changes a substance can be transformed from one phase to another while transformed from one phase to another while retaining its chemical properties. retaining its chemical properties.

• For example, water is still water whether it is in liquid For example, water is still water whether it is in liquid form or frozen into an ice cubeform or frozen into an ice cube

States of Matter• Matter exists in 4 phases

– Solid– Liquid– Gas– Plasma

Solids• Solid is a state of matter that has a definite

volume and a definite shape

• Particles in a solid vibrate back and forth within the solid

Which of the pictures on the right Which of the pictures on the right shows a solid?shows a solid?

– Takes up space Takes up space – Does not take the shape Does not take the shape

of its container of its container – Does not fill a container Does not fill a container

larger than itself larger than itself – Has mass Has mass – Has a definite shapeHas a definite shape

Liquids

• Liquid is a state of matter that has no definite Liquid is a state of matter that has no definite shape but has a definite volume.shape but has a definite volume.

Liquids

Particles in a liquid are free

to move around each

other, a liquid can flow from place to place

Which of the pictures on the Which of the pictures on the right shows a liquid ?? right shows a liquid ??

– Takes up a definite Takes up a definite amount of space amount of space

– Has massHas mass– Takes on the shape of Takes on the shape of

its container its container – Does not fill a container Does not fill a container

larger than itself larger than itself – Has no definite shapeHas no definite shape

Gases

• Gas is a state of matter with no definite shape or volume

• When liquid water is boiled it becomes a gas. The When liquid water is boiled it becomes a gas. The gaseous water molecules travel at a very high rate gaseous water molecules travel at a very high rate of speed and never stand still.of speed and never stand still.

Which of the pictures on the right is Which of the pictures on the right is a Gas???a Gas???

– Has massHas mass

– Takes up space Takes up space

– Spreads out to fill Spreads out to fill its containerits container

Plasma

– PlasmaPlasma is a state of matter in which atoms are is a state of matter in which atoms are stripped of their electrons and the nuclei are stripped of their electrons and the nuclei are packed closely together packed closely together

– ExampleExample: lightning and material in neon lights: lightning and material in neon lights– Rare on Earth, but common in the universe.Rare on Earth, but common in the universe. – These are gases which have been heated to an These are gases which have been heated to an

extremely high temperature, such as the temperature extremely high temperature, such as the temperature inside the sun (stars) inside the sun (stars)

• The end…..