Year…8 . Elements Compounds Mixtures

Year 8 ELEMENTS, COMPOuNDS & MIXTURES

(and some states of matter) Chapter 6 and 7



Key Concepts
Words To Learn




  1. 1. States of matter (Chapter 6): Solid, Liquid, Gas and the properties of each.
  2. 2. Elements (Chapter 7): Atoms & Elements, Inside the Atom, Atomic Numbers, What’s In A Name.
  3. 3. Grouping Elements: Metals & Non-metals
  4. 4. Patterns, Order & Organisation: Looking For Similarities
  5. 5. Compounding The Situation: Splitting Water
Solid, Liquid, Gas, Melt, Evaporate, Freeze, Condense, Sublime.

Atom, Proton, Neutron, Electron, Nucleus
Atomic Number, Chemical Symbol,
Element, Compound, Mixture
Metals, Non metals, Metalloids

Periodic table, Period, Group, Inert, Noble gas,
NAME:

Science Quest 8
TEXTBOOK
PRACTICALS / ACTIVITIES
SCIENCE Quest 8
Understanding
ACTIVITIES
Established Extending
1
6.1 States of Matter: Pg 210
Complete AssessOn Readiness Test (CH 7 only).
6.1 Read States of Matter page 210 & complete Investigation 6.1 Comparing Solids, Liquids & Gases
6.2 Read Changing States page 212
EP. Chemical Science>States of matter
Understanding & Inquiring
page 211 Q’s 1, 2, 3, 5
page 213 Q’s 1, 2, 5, 6, 8

EP. Chemical Science>States of matter> L.S.G
Understanding & Inquiring page 211 Q 8
page 213 Q 9

EP > states of matter>measuring mass and volume etc
Do Discuss & Explain on page 211 Q 10
page 213 Q 10

EP states of matter> density and measuring the effects of heat and pressure
2
7.1 It’s Elementary:

Pg 228
7.1 Do Investigation 7.1: How Small Are The Bits That Matter page 227.
Do Investigation 7.3: Checking Out Appearances page 229.

EP. Chemical Science>Types of substance

Harry He Likes Beer - ppt activity
Understanding & Inquiring
page 229 Q’s 2, 3, 7

EP. Chemical Science>Types of substances > matter atoms and elements
Understanding & Inquiring page 229 Q 9
Understanding & Inquiring page 229 Q 10
3
7.2 Elements: The inside Story
structure of the atom and calculating the number of protons etc
Pg 230
Read theory on Pg 230 to 232.
Understanding & Inquiring
page 232 Q’s 2, 3, 4, 6, 7, 8
Understanding & Inquiring
page 232 Q’s 9 - 12
Understanding & Inquiring
page 232 Q’s 13, 14
* INVESTIGATE – Complete EITHER Q17 (uses and symbols) or Q18 (Nanotechnology) on Page 232 or Q9 on Page 237
4
7.3 Compounding the Situation Pg 233
Read theory on Pg 233 to 234.
Do Investigation 7.5 Making a Compound from its Elements page 234.
Do Investigation 7.6 Let’s Collect an Element page 235.
Understanding & Inquiring
page 235 Q’s 1 – 6, 10

EP. Chemical Science>Types of substances > molecules and atoms and elements.

EP. Chemical Science>Chemical reactions including- properties and reactions

EP. Chemical Science> Chemical reactions>New compounds
5
7.4 Grouping Elements Pg 236
the difference between metals and non metals
Read theory on Pg 236.
Do Investigation 7.7. Looking for Similarities page 237.
Understanding & Inquiring
page 237 Q’s 1 – 6
Understanding & Inquiring
Page 237 Q 8

6
7.5 Pattern, Order & Organisation Pg 238
Read Theory on Pg 238 – 239.

Label your own copy of the periodic table.
Understanding & Inquiring
page 239 Q’s 2, 3
Complete It’s Elementary Interactivity Int-0229
7
7.6 Making Molecules Pg 240
Read Theory on Pg 240 -241.
Do Investigation 7.8 Mix N Match page 240.
Understanding & Inquiring
page 241 Q’s 1, 2, 3, 5, 6
doc-6070
Complete Making Molecules Interactivity int-0228
Beyond the levelwriting compounds and chemical reactions
8
Revision / Test
Complete Looking Back Page 245 – 246, Q 1 – 19.
Complete AssessOn Progress and/or Topic Test.













Class notes

Solids Liquids and Gases

Solids have a definite shape and can not be compressed. Solids can be heated and once they reach a certain temperature they melt and become a liquid. If we keep heating them till they boil (boiling point) they become a gas.

Liquids take on the shape of their container and can not be compressed. If you heat them to their boiling point they become a gas. If we cool them to their freezing point they become a solid.

Gases fill their containers and can be compressed. If we cool them to below their boiling point they become a liquid. If we keep cooling them to below their melting point they become a solid.



Draw a picture to represent the particles arranged in a solid

Draw picture of the arrangement of particles in a liquid

Draw a picture of the arrangement of particles in a gas


The periodic table and the first 20 elements


  1. Know the name and symbol of the first twenty elements
  2. You can get this information off your periodic table -- click here to download a periodic table
  1. Here are some more common elements you should know

Name

Symbol

Iron
Fe
Copper
Cu
Zinc
Zn
Tin
Sn
GOLD

SILVER

Lead

Uranium

Nickel


And here are some common compounds
Complete this table

Name

Symbol

The elements that make it up

The number of each element

Water
H2O
Hydrogen and Oxygen
2 Hydrogen and 1 Oxygen
Hydrochloric acid
HCl
Hydrogen and Chlorine

Sodium Chloride (table salt)
NaCl
Sodium Chloride

MagnesiumChloride
MgCl2


Rust
FeO


Copper sulfate
Cu SO4








How to measure the volume of an irregular object

steps 1 - fill a measuring cylinder to 50 mL
step 2 add the irregular object - measure the new volume
step 3 subtract 50 from the new volume - this is the volume of the irregular object
eg 55 - 50 = 5mLs


Using the particle model to explain Melting and Boiling

Melting happens when the particles in a solid move so rapidly that the forces holding the particles very close together are broken and the particles start to move out of the solid's regular shape.
We say solid melts and becomes a liquid.

If the particles gain enough energy to move very rapidly they escape their liquid friends and move into the state of matter called GAS.

As a general rule Gas particles have the most energy and move very very fast
Liquid particles have a fair amount of energy and can gain energy (get hotter) to become a gas or lose energy (get colder) to become a solid.
Solid particles are moving but slowly and hold the shape of their solid.If you add energy to a solid the particles will move faster and if you add enough energy they will move to the liquid state.

Start questions p 221 - but only do 2,3, 5, and 9,
Then start Changing boiling point of water wksheet.

Atomic number and mass

When we write an element's symbol we often include two numbers. These are written to the right of the symbol. The atomic mass ( its always bigger). The other number is the atomic number. Here is an example Carbon has an atomic mass of 12 and its atomic number is 6.
Atomic mass = the atomic number (this is the number of protons) + the number of neutrons.
Atomic number = the number of protons.
the number of protons = the number of electrons.
Question
how many protons and neutrons does an atom of the element sodium have?
Step 1 look up the element on the periodic table
Step 2 find the atomic number ( the rule is that the atomic number always tells us the number of protons) for sodium its 11
Step 3 find sodiums atomic mass (for sodium its 23)
step 4 the rule is Atomic mass - atomic number = the number of protons - for this example 23 - 11 = 12 there are 12 neutrons


The periodic table

This is a useful tool because it tells you
  1. the atomic mass
  2. the atomic number
  3. and the position of the element in the table tells you how the electrons are arranged and orbit around the nucleus.

REview of Solid Liquid Gases

yr 8 SLG photo.JPG
yr 8 SLG photo.JPG

Solid Liquids and gases. As you increase the energy of a solid it melts to become a liquid. Even more energy will boil it to become a gas. The transformation names are also shown


Structure of the atom and determining the number of protons neutrons and electrons

The arrangement of electrons around the nucleus is unique to each element when in its natural state. The diagram below shows the pattern. In this example there are 2 electrons in the innermost oribital (there can only be a maximum of 2 in this orbit and it must be filled before the next orbit can be populated.
in this example there are 5 electrons in the outer orbit. This orbit will have a maximum of 8 electrons.
so for nitrogen that has an atomic number of 7 and an atomic mass of 14 it will have 7 electrons that have a negative charge orbiting the nucleus that will have 7 protons that have a positive charge. These charges are equal therefore thet balance out.

using the rules above we can calculate the number of protons. We always assume electrons weigh zero as they are extremely tiny about one billionth the mass of a proton. So the atomic mass is the combined mass of protons and neutrons. So if we know the atomic mass is14 and the atomic number ( ie proton number) is 7 then the number of neutrons must be 14-7=7 neutrons. Go below to review the first twenty elements .
yr 8 Nitrogen structure photo.JPG
yr 8 Nitrogen structure photo.JPG

Atomic mass = number of protons + number of neutrons






Looking for Similarities Prac
Grouping Elements
Aim: to collect information about different elements and then try to group them based on these observations

Results
Element............
...
Shiny or Dull.....
...
Does it bend.....
....
Does it Conduct Electricity
S
d
n

Zn
s
y

Sn



C



Si



Cu




Looking for Similarities Prac

the differences between metals and non metals

Element............
...
Shiny or Dull.....
...
Does it bend.....
....
Does it Conduct Electricity
S
d
n
n
Zn
s
y
y
Sn
s
y
y
C
d
n
y
Si
s
n
y
Cu
s
y
y

Conclusion
Metals are all those elements that can conduct electricity, bend and are shiny. Non metals are dull , brittle and can not conduct electricity. Metaloids have some properties of metals eg shiny and conduct electricity. But they also have non metal properties like being dull or brittle.


Ques 7 Two suitable groups for our elements would be metals (Zn, Sn, Cu) and metalloids (C, Si)
S is a non metal

Ques 8 The element that does not seems it could be in ether group is S

Conclusion
All metals can conduct electricity and are shiny when cut and can be bent.
Carbon in the form of graphite conducts electricity BUT carbon in the form of diamonds or coal does not. (this is because of the way the carbon atoms bond with each other in each of theses forms. Carbon in graphite makes layers )

HMWK: - learn the symbols and name of the elements in our table.

Complete the ques 1- 7 p 245.

The first twenty elements

the first 20 elements - use the periodic table to complete this table
remember
Protons + neutrons = atomic mass
(therefore atomic mass - protons = neutrons)
Atomic
Number
Name of the element
Symbol
Atomic mass
number of protons
Number of neutrons
1
Hydrogen
H
1
1
0
2
Helium
He
4
2
2
3
Lithium
Li
7
3
4
4
Beryllium

9
4
5
5
Boron

11
5
6
6
Carbon

12
6
6
7



7

8



8

9



9

10



10

11
Sodium
Na



12





13





14





15





16





17
Chlorine
Cl



18





19





20
Calcium
Ca

20

And here are some others you should know







Fe





Ni





Cu



30







As





Ag





Au





Pt





Hg





Pb







Answers to
Activity 6.1

Investigating particlesdoc-6066 answers
  1. Give an example of a solid.
Solids have fixed shape, volume and mass.
  1. Give two examples of a fluid.
A fluid is either a liquid or a gas. Two common fluids are water and air.
  1. What is the unit for mass?
The unit for mass is the kilogram (kg).
  1. What is a common unit for volume?
Common units for volume are the litre (L) and cubic centimetre (cm3).
  1. State the word used to describe a solid turning into a liquid.
Melting
  1. Describe the process of condensation.
During condensation, a gas changes state into a liquid.
  1. Material A has a melting point of 34°C whereas material B has a melting point of 56°C. Both materials are placed in an oven at 50°C. Describe the state of each material after being in the oven for a period of time.
Material A would be a liquid as the oven temperature is above its melting point. Material B would be a solid as the oven temperature is below its melting point.
  1. What does a thermometer measure?
Thermometers measure temperature.
  1. State the four key assumptions of the particle model for matter.
Assumptions include:
  • All substances are made up of tiny particles.
  • The particles are attracted towards other surrounding particles.
  • The particles are always moving.
  • The hotter the substance is, the faster the particles move.
  1. Use the particle model of matter to describe a solid.
In a solid, all particles vibrate but stay in the same position relative to each other. The amount of vibration depends on the temperature of the solid.
  1. Use the particle model of matter to explain why a solid expands when heated.
When a solid is heated, the energy of the vibrating particles increases; they vibrate faster so the average distance between surrounding particles increases. This causes the solid to expand.
  1. What happens to the temperature of a solid when energy is transferred to it?
The temperature of a solid increases when energy is transferred to it. If the temperature increase is sufficient, the solid will melt to become a liquid.
  1. What is diffusion?
Diffusion is the movement of particles through a substance that is either a liquid or a gas.
  1. What are clouds composed of?
Clouds are composed of condensed water vapour that is present in the air.