Unit 2

Science 7

Chemistry

Unit 2.1The Four States

02

01

• Are ice, water, and water vapor the same type of matter?

• How is a mixture of sugar-water different than a mixture of sand-water?

• How does pure water differ from tap water?

Matter: ________________________________

Matter is anything that has _____________ (takes up space) and has a _____________ (contains a certain amount of material). Matter doesn’t have to be visible (even air is matter). All matter is made up of _____________ that are constantly moving. The motion of the particles and the strength of _____________ between the particles determines a material’s state of matter. Some characteristics of matter that can be observed with your senses are _____________, _____________, _____________, _____________ and _____________.

The Four States of MatterAnything that has mass and volume

massvolume

atomsbond

sight tastesmell touch sound

There are three familiar _________________: solid, liquid, and gas. Plasma is a fourth state of matter that only occurs at extremely high temperatures. Plasma is like a gas, but it can conduct electricity. It is found in stars, lightening, and neon lights.

States of matter

States or Phases of Matter  The three main states of matter are: ____________________ An example is ___________________ ____________________ An example is ___________________ ____________________ An example is ___________________

solid

liquid

gas

ice

water

steam

 SolidsHave a definite shape and volume. This means that solids keep their shape and take up the same amount of space.

 LiquidsHave a definite volume but no definite shape. Liquids will take the shape of the container in which they are placed.

 GasesHave no definite volume or shape. The gases will expand to fill any container and will take the shape of the container.

 PlasmaHas no definite shape or volume and is a highly energized gas. Plasma is common in the universe; it is not common on Earth.

plasma

gas

liquidsolid

condensation

evaporation

freezing

melting

 

STATES OF MATTER IN DETAIL

 Write SOLID, LIQUID, or GAS in the table to match the diagrams.

Solids have a definite shape and volume.• This means that solids ______________and

take up the same amount of space. Solids have a high cohesive force so the molecules of solids are packed __________ together. The cohesive force is the __________________. Molecules are in constant motion; however, in solids, the molecules are ______________ you can’t see them move.

Keep their shape

tightlyattraction

moving

• Liquids have ________________________. Liquids will take up the same amount of space but will ________________ in which they have been placed. At the molecular level, the liquids have a ______________________, so the molecules of a liquid are spread far enough apart that they can flow over each other and ____________________________

a definite shape but no fixed volume

will take the shape

low cohesion force

move a little faster

• Gases have _______________________. The cohesive force of gases is __________________, so the molecules are _____________________. The gases will_______________________ and will take the shape of the container.

No shape or volume

Almost nonexistent

Not attracted to one anotherExpand to fill the container

• Plasma has ________________________ and is a __________________ gas. As with other gases, the cohesive force of plasma is ___________, so the molecules are __________________. The gases will ____________ and will take the shape of any container.

No shape or volumeHighly energized

Non-existentNot attracted to one anotherexpand

Movie on states of matter

Homework Check Fill in the blanks:

Matter is everything that has ________________ and ______________________There are four states of matter: ________________, ______________, _________________ and ________________._______________ is a fourth state of matter that only occurs at extremely high temperatures. Plasma is like a ______________ and is found in stars, lightening and neon lights.

massweight

solidliquid gas

plasmaPlasma

gas

Homework Check

 True or False______ Matter is anything that is made up of volume and mass______ Solids can change their shape______ Liquids have no definite shape or volume______ Gases have no definite shape or volume______ Plasma is a highly energized gas

T

TF

T

T

 

So, why do so many people wish to have plasma television?

Unit 2.2The Structure of Matter

02

02

• This study of chemistry begins with an examination of ______________. There are two theories about the ______________ of matter: atomic and molecular. ________________ states that matter is made up of atoms.

____________________ states that matter is made up of molecules. Matter has been classified into states, or phases, of matter: solid, liquid, gas and plasma.

mattertheories

Atomic theory

Molecular theory

 What is a model?

   

Why do scientists use models?  

The Five Key Points of the Particle Model 

All matter is made up of particles

Particles have empty space between them

Particles at higher temperatures move fasterEach pure

substance has its own particle

Particles are always in motion

Using the Particle Model• Draw sketches to show how the particle

model explains the properties of a solid, a liquid, and a gas. For each state indicate the distance between particles, type of movement, and whether or not it has a fixed (definite) shape and volume.

Homework Check

Use the Particle Model of Matter to describe (in words and pictures) each of the following in more detail:•  the spacing between particles of a solid 

•  the movement of particles in a gas

 •   the movement of particles in a solid

• the spacing and movement of the particles in a liquid

Closely packed

Random- move quickly; no cohesion

Slowly; vibrations

A little faster. No cohesion

• Imagine that the students in your class represent particles of matter and the school gym represents a container. Use labeled sketches to show how you would organize the students in the gym to demonstrate a change of state from solid to liquid.

 

 BONUS: $10 ClementBucks • Some scientists (mainly physicists) consider there to be

two other states of matter that exist only at extreme temperatures: plasma and Bose-Einstein condensate. Use the Internet to find out about these two states.

Unit 2.3The Physical Propertiesof Matter

02

03

    

  

 

All matter can be detected and ________________________. Physical

properties of matter that can be measure include _________,

___________ and ______________. Mass is the ______________ of

______________ and it remains constant. The metric base unit of

measure for mass is the __________. Mass can be measured using a

triple beam balance. Volume is how much space something takes

up. The volume of regular shaped objects, such as a block of wood

may be found __________________. Measure the object’s

____________________________. Multiply the three measurements

(LxWxH). The answer is labelled in cubic centimeters.    

  

measured

mass denisity volumeamount matter

gram

with mathematics Length, width and height

When measuring the volume of a liquid, a __________________ may be used. The basic unit for measurement is the ______________ (mL) for a liquid. When reading a graduated cylinder, the liquid has a tendency to cling to the sides of the container, creating a curve called a ______________. The tendency of unlike materials to be attracted to each other is called adhesion. When reading the volume, you must measure from the bottom of the curve.

 

 

  

Graduated cylindermilliliter

meniscus

The volume of an irregular object, such as a rock , can be found using a method called ______________. Water is added to a graduated cylinder and recorded. Once the volume of water has been recorded, the rock is added and the level of the water is recorded again. The ______________ between the first measurement and the second is the ______________ of the rock.

displacement

differencevolume

    

  

 Density is the relationship between the _______________ of an object. The more ______________ the molecules, the greater the density of an object. By finding the mass and volume of the object, you can find the mathematical density. It can be calculated by ______________ the mass by the volume.  • For Example: Density = mass/voume or = D= MV

Knowing the relationship of mass, volume, or density will help you determine whether an object will ______________ in a liquid. If the object’s density is greater than the density of the liquid it is in, the object will not sink.

Mass and volumeclosely

dividing

float

HOMEWORK CHECKWhat is volume?    Liquids and gases are usually measured using the metric unit __________ and its prefixes, and solids are usually measured using _______________. Estimate the volume of the following familiar objects and then compare with other students. Can of pop _____mL measuring cup _____mL carton milk __ L ____ mL tablespoon(Tbsp) ____mL teaspoon(tsp) ____mL

    

  

 The mathematical formula for the volume of a cube is

Volume is either directly or indirectly measured. Using a

graduated cylinder to measure a certain volume of liquid is an

example of ___________ measurement. Another example of

direct measurement is _____________________________________.

An example of an indirect measurement is

___________________________________. 

Unit 2.4Measuring Mass & Weight

02

04

Background:

The difference between mass and weight is confusing because on Earth, we are always in the presence of Earth’s gravity (9.8 N/kg). Everything has weight. We describe objects as being heavy or light.

The only time things can be weightless on Earth, is when they are falling freely and not supported by the Earth.

We usually find the weight of objects by using spring scales, such as a typical bathroom scale that you stand on. Gravity pulls on you towards the ground and causes the spring to compress, depending upon how much mass your body has.

A large body mass will be heavier than a small body mass.

WEIGHT is how heavy an object is, and MASS is how much substance or matter is in the object.

  

• Now here’s the confusing part: Weight is suppose to be measured in Newtons (N), and mass in grams (g), kilograms (kg), or sometimes in pounds (lbs).

We never talk about Newtons. Because we never leave Earth’s gravity to experience how different gravitational forces change our weight, we don’t need to distinguish between mass and weight.

So, on Earth, we think of mass and weight as the same. Please remember though that they are not the same.

MASS VS. WEIGHT

MASS: Mass is the amount of matter in an object, measured in grams (g) or kilograms (kg) etc. The non-metric system uses pounds for mass.

 

The mass of an object does not change if the gravitational force changes. For example, the mass of an astronaut is the same on earth as it is on the moon, even though the moon’s gravity is 6 times less.

WEIGHT: Weight is measured in Newtons (N), named after Sir Issac Newton. The weight of an object is dependent on gravity.  The weight on an object changes if the gravitational force changes. Weight = mass x gravity. A greater gravitational force pulling down on you makes you heavier. In outer space you are weightless. For example: Comparison of a 80 kg astronaut. The astronaut has no weight in outer space, and is about 6 times heavier on earth than the moon.

.

When we use the term weight in our every day

conversations to represent how heavy an object is we do

not use the correct units of measurement. We should be

using the units Newtons (N) instead of kilograms or

pounds. However, because we do not travel to different

gravitational force fields, which would affect our

measurement of weight, the terms mass and weight can

be used interchangeably on earth.

1000

1000

1000

1000

1000

1000

9.8

1.6

0

9800

1600

0

LAB #4a Density Tower

In this investigation you will compare the density of a variety of liquids.

Viscosity is ____________________________________________

Density is _____________________________________________

Driving Question: Are some liquids denser than others?

Hypothesis: _____________________________________ _______________________________________________

Materials: 100 mL graduated cylinder, small 100mL beaker, glass stir rod, food colouring, petri-dish containing solid objects

Liquids: 20 ml each of vegetable oil, glycerin, yellow-coloured water, red-coloured isopropyl

Solids: paper clip, sliver of candle wax, plastic thumbtack, popcorn kernel, wood shaving

PROCEDURE:

1. Work in groups of 3. Collect all materials and take them to a work area.

2. Find mass of the 100mL beaker BEFORE adding a liquid MASS OF BEAKER = ________

3. Carefully pour 20 mL WATER into beaker and find mass BEAKER + LIQUID = _________

4. Calculate MASS OF (BEAKER + LIQUID) – MASS OF BEAKER = ___________ = mass 20 mL water

5. Record mass of water in the table below. The mass of the other liquids is done for you.

6. Use your fingers to feel the liquids. Describe their texture and relative viscosity in the table. Use as many qualitative descriptive words as possible.

7. Infer the relative densities based on touching and swirling the liquids. Record in the table.

7. Add ONE DROP of food colouring to the alcohol (red) and water (yellow).

8.Carefully pour the following 3 liquids into the graduated cylinder in the following order: GLYCERIN, VEGETABLE OIL, and WATER - do NOT pour in the alcohol

9.Let the liquids settle and then DRAW what you see in the diagram on the opposite page. Be as accurate as possible. Draw in the graduated cylinder measurements.

10.Carefully drop in ONE or TWO drops of green or blue food colouring and observe what happens.

11.Following your teacher’s instructions, use a glass stirring rod to carefully pour in the ALCOHOL.

12.Add the alcohol to your drawing.

13.Now carefully add the solid objects one at a time, observing how they move through the liquids. Add the label the solid objects to your diagram.

LAB #4b Density Blocks

In this activity, you will be comparing blocks of DIFFERENT DENSITIES. Each block has the SAME VOLUME as other blocks, but a DIFFERENT MASS.

Driving Question: Are some solids denser than others?

Hypothesis: _____________________________________ _______________________________________________

Materials: set of blocks

Procedure:1.Complete the first empty column in the table below. Decide whether each block is made of metal, wood or plastic.2.Make your prediction as to whether or not a block will sink or float in a beaker

of water.3.Carefully slide each block into the beaker of water and record if it sinks or

floats.4.Complete the final column of the table after discussion with your group.

True or False Something that has a very low density has only a small amount of matter occupying a large amount of space. In other words, it has a low mass but a high volume. True or False Density is a chemical property of matter. True or False Density is a quantitative property of matter. True or False Density is calculated by dividing the volume of matter by its mass. True or False One gram of pure water occupies exactly 1.0 mL of volume. True or False The density of pure water is 1.0 g/mL. True or False. Anything with a density greater than 1.0 g/mL will sink in pure water. True or False Something that is very dense has a lot of matter taking up a very small amount of space. True or False The most appropriate unit for measuring the volume of your body is mL. True or False In general, mL, L, kL are used to measure the volume of liquids and mm3, cm3, m3 are used to measure the volume of solids and gases. True or False

If you have 1000 cm3 of pure copper and 1000 cm3 of Styrofoam peanuts, which has the greater...mass? Explain how you know this true.   volume? Explain how you know this is true.   density? Explain how you know this is true.   

You have exactly 500 mL of each of four (4) different liquids labeled 1, 2, 3, and 4. Liquid 1 floats on 2, 2 floats on 3, and 3 floats on 4. a) Draw a labeled diagram to show their relative densities.    Which liquid has the greatest mass? Explain how you know this is true.   Which liquid has the lowest density? Explain how you know this is true.

As you go down in depth in the ocean, the water temperature decreases and the salinity (amount of salt) increases. Which has the lower density...

salt water or fresh water? Use the Particle Model of Matter and a labeled diagram to explain your answer.

cold water or warm water? Use the Particle Model of Matter and a labeled diagram to explain your answer.

cold salt water or warm fresh water? Use the Particle Model of Matter and a labeled diagram to explain your answer.

Which has greater density?

1 mL of isopropyl alcohol or 1 litre of isopropyl alcohol?

A lead weight used for fishing salmon or a classroom full of chicken feathers?

Unit 2.5Review

02

05

Solids, liquids and gases have definite characteristics. A

solid has a ________________________. Solids resist being

____________ ____________. Another characteristic is

____________. Elasticity means that a solid can be bent or

twisted a limited amount, and it will return to its former

shape. A rubber band is a solid that can easily be

stretched, and then it will return to its original shape and

size. Some solids are also ____________, which means the

solid can be formed into new shapes. Gold is a solid that

can easily be hammered into a thin sheet.

A liquid has a definite ____________. but takes the __________ of the container holding it. When water is poured from one container into a container shaped differently, the water takes the shape of the new container. Other physical characteristics of liquids are _______________ and ________________. Adhesion is the attraction between unlike substances. When measuring liquid volume, your read the measurement from the bottom of the meniscus. The _________ is the ____________ formed because of the adhesion of liquid to the container. Liquids also have _______________. When a thin straw or glass tube is dipped in a liquid, the liquid will _________ _____________ in the straw or glass tube. This concept explains why coloured water seems to climb up a paper towel.

Water molecules are ________________________ because of a force called _______________. Cohesion is the attraction of like substances. As the molecules cling to each other, they form an invisible “skin” on the surface of the water, or what scientists call ________________________. Surface tension helps a drop of water hold its shape, to hang on to itself, and to stack up on a surface. It also helps some insects walk on the surface of water.

When you pour a liquid from one container to another, the

liquid takes ________________________. The molecules of

liquids are spread far enough apart they can flow over

each other and more freely than in a solid. Some liquids

flow more freely than others. A liquids resistance to flow

is known as the liquid’s ____________. The slower a liquid

flows, the higher the viscosity. Honey has a high viscosity,

while water has a low viscosity.

Fluids move from one area of high pressure to one of low pressure.  Example. When you suck air out of the top of a straw, you reduce the air pressure at the top of the straw. Normal atmospheric pressure then forces liquid from your drink up the straw to your lips.

Gravity pulls on fluids. Pressure in any contained quantity of fluid will increase with depth. Example. When holes are places in a container, water will squirt out farthest from the hole nearest the bottom of the container

Water exerts an upwards force on objects. The pressure pushing up on an immersed object is greater than the pressure pushing down on it. The force is known as buoyant force. “Archimedes Principle” explains why objects sink or float. If the buoyant force (upwards force) is equal to the weight of an object, the object will float. If the buoyant force (upwards force) is less than the weight of the object, the object will sink Example. If you jump in a tub, you will notice that the water exerts an upwards force that keeps you from sinking the bottom right away.

Bernoulli’s Principle reveals that the pressure in a moving stream of fluid is les than that in the surrounding fluid.  Example. A plane’s wings are curved on top and flat on the bottom. Air must travel farther (and faster) over the surface then the bottom, providing a net upwards force beneath the wing.