Physical Science, Ch. 14 pg. 432-439, Ch. 15 pg 462-476

Physical Science, Ch. 14 pg. 432-439,

Ch. 15 pg 462-476

Today’s Learning Objectives

1. Define Kinetic Theory.

2. How do particles move in the four states of

matter?

Matter & Thermal Energy (14-1)

Kinetic Theory - Matter is made of constantly

moving particles

Details:

1. All matter is made of tiny particles

2. They move in constant, rapid, random

motion

3. They collide

4. They lose very little energy in the collisions

Matter & Thermal Energy

Solids have particles that sit and vibrate

Liquids have particles that slide by each

other

Gases have particles that bounce

randomly

link

http://phet.colorado.edu/en/simulation/states-of-matter


States of Matter –

The physical forms in which a substance can exist

The Four States of Matter –

1. Solid

2. Liquid

3. Gas

4. Plasma


Solid – the state of matter with a

definite shape and definite volume

Ex. Ice, chrome bumpers, glass

Particles vibrate in place, attracted to

each other

Class demo


Liquid – The state of matter with an

indefinite shape, but has a definite

volume

Particles move faster, less attracted to

each other

Class demo


Gas – The state with an indefinite

shape and indefinite volume

Particles move fastest, not attracted to

each other

Examples?

Class demo


Plasma – like a gas, but made up of

charged particles

99% of matter seen in universe is plasma

Examples:


Temperature: the measure of the

average kinetic energy of the particles

of a sample of matter


Describe the six state changes.

Learn the terms in this chapter.

Start boiling demo now!


Changes of state – changing from a

solid to liquid, etc.

Types:

Melting Freezing

Vaporization Condensation

Sublimation Deposition


Melting – change from a solid to a liquid

The particles are becoming less orderly (link)

Freezing – change from liquid to solid

The particles are becoming more orderly

Melting point = freezing point

Heat of Fusion – the energy required to change a substance from a solid to a liquid at melting point

http://phet.colorado.edu/en/simulation/states-of-matter-basics


Vaporization – change from a liquid to gas (link)

Could be boiling or evaporating

The particles are becoming less orderly

Condensation – change from a gas to liquid

The particles are becoming more orderly

Boiling point = Condensation Point

Heat of vaporization – the amount of energy

required for the liquid at its boiling point to become a

gas

http://phet.colorado.edu/en/simulation/states-of-matter-basics


Boiling vs. Evaporating

Boiling is vaporization throughout the entire liquid because it is all at the boiling point

Evaporation is vaporization only at the surface, this occurs below the boiling point


Sublimation – Change from a solid to gas (directly)

Particles become much less ordered

Ex: Ice on road disappearing on a very cold, sunny day w/o melting first OR dry ice

Deposition – Change from a gas to solid (directly)

Particles become much more ordered

Ex. Frost forming on window


While a substance changes state, its

temperature does not rise or fall until

the phase change is complete

See graph called

a “heating curve”

Label the Graph

line AB =

line BC =

line CD =

line DE =

line EF =


Thermal expansion: an increase in the

size of a substance when the

temperature is increased

Can also contract when cooled

Ex. – thermometers

Thermal Expansion demo(s)!


o What are the differences between pure

substances and mixtures?

o How are elements and compounds

identified?

o How are suspensions, solutions, and

colloids related?

Composition of Matter (15-1)

o What about that introductory activity

has anything to do with matter?

o Answer:

Matter has properties. These

properties can be used to identify what

type of matter it is.

Composition of Matter

o Matter – anything that has mass and

takes up space

o What are some examples of matter in this

room?

o What does NOT qualify as matter in this

room?


o Matter has two types:

1. Pure substances

2. Mixtures

o Pure substance – matter that always has exactly the same composition

o Note: your book sometimes uses the word “substance” instead of pure substance


o 2 types of pure substances

1. Elements

2. Compounds

o Element – a pure substance made up

of atoms that are all alike

o Examples?


o Elements are made of only one of the

100+ kinds of atoms

o Atom – the smallest particle of an element

oEach kind of atom has unique

properties that make it different than

the other kinds of atoms


o Compound – a substance in which the

atoms of two or more elements are

combined in a fixed proportion


o Compounds have different properties

than the elements that make them up

o Ex. sodium chloride (NaCl)

o Compounds cannot be separated into

their elements by physical means

o So you cannot filter, boil, or manually cut out

the different elements

http://www.schooltube.com/video/2fa9cb3e39064832b31d/Reaction of Sodium and Chlorine


o If matter is not a pure substance, it is a mixture

o Mixture – matter composed of 2 or more different substances that can be separated by physical means

o Examples?

o Mixtures can contain varying amounts of each substance.

o Does every cookie have the same number of chocolate chips?


o 2 kinds of mixtures

1. Heterogeneous mixtures

2. Homogeneous mixtures

o Hetero – different

o Homo – same


o Heterogeneous mixture – a mixture in

which different materials remain

separate

o Examples?


2 kinds of heterogeneous

mixtures

1. Suspension – a

heterogeneous mixture of a

liquid and solid particles that

settle out

2. Colloid – a heterogeneous

mixture with particles that

never settle out


o Homogeneous mixture – a mixture that

stays uniformly mixed and whose

particles are so small they cannot be

seen with a microscope

o Examples?

o Solution – another term for homogeneous

mixture



What are physical and chemical

properties?

Compare and contrast physical and

chemical changes.

How does the Law of Conservation of

Mass apply to chemical changes?

Properties of Matter (15-2)

o Physical property – any characteristic

of a material that you can observe

without changing the identity of a

substance

o Every substance has a specific

combination of physical properties that

make it useful for certain tasks

Properties of Matter

o Some examples of physical properties

Density

Viscosity

Freezing point

Boiling point

Conductivity

Hardness


o Important to recognize physical

changes

o Physical change – a change in size,

shape, or state of matter in which the

identity of the substance remains the

same

o Examples?


Physical changes can be used to

separate mixtures

Ex. distillation


o Chemical property – any characteristic

of a material that you can observe that

produces one or more new substances

o 2 examples of chemical properties

1. Flammability

2. Reactivity


Chemical change – when one

substance becomes another substance

2 Na + Cl2 → 2 NaCl

http://www.schooltube.com/video/7b6c78aa959c5d75c09b/Ionic and covalent bonding example


o Methods of recognizing chemical

changes

1. Change in color https://www.youtube.com/watch?v=BqeWpywDuiY

2. Production of gas

3. Production of energy (demo)

4. Formation of a precipitate (demo)

o Precipitate – a solid that forms

when two liquids are mixed


o These 3 methods are not perfect

ChangeChemical or

Physical change

Mix baking soda and vinegar Chemical

Water boiling Physical

Mix Kool-Aid powder in water Physical

Banana turning black Chemical

Mix milk and lemon juice Chemical

Mix melted butter and ice water

Physical


o Bottom line:

If a new substance was formed, it was a

chemical change.


Law of Conservation of Mass – the

mass of all substances before a

chemical change must equal the mass

of all substances after a chemical

change

Ex.

2 𝐻2+ 𝑂2 → 2 𝐻2𝑂

Physical Science, Ch. 14 pg. 432-439, Ch. 15 pg 462-476

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