1. SNC2D Grade 10 Science - academic
Chemistry review: grade 9

2. What is “Matter”? Examples?
Matter = any substance with Mass & Volume (takes up space) 2

3. Properties of matter
A physical property is a characteristic of a substance that can be observed or measured without changing the substance’s composition (i.e. ice is still water). Some physical properties:
Physical Properties of Matter
1 – colour
2 – texture (fine, coarse, smooth, etc)
3 – odour (odourless, spicy, sharp, etc)
4 – luster (shiny, dull, vitreous, etc)
5 – taste (sweet, sour, bitter, etc)
6 – hardness (measure of resistance of been scratched. A harder material will scratch a softer one. Diamond will scratch glass. Nail will scratch a chalk)
7 – Solubility (ability of a substance to dissolve in a solvent like water. Salt is soluble and pepper is insoluble)
8 – Viscosity (how easily a liquid flows. Maple syrup is more viscous (“thicker”) than water
9 – state (whether is solid, liquid, or gas at room temperature)
10 – melting and boiling points (temperature which substances change state. Liquid water changes to vapour at 100 0C and become solid ice at 0oC) 3

4. Properties of matter
A description / statement of whether or not a substance reacts with another substance to form a new compound is a chemical property of matter. Examples below:
Chemical Properties of Matter
1 – Combustibility: ability of a substance to react with oxygen to produce carbon dioxide, water, and energy when exposed to flame. Gasoline is combustible (= flammable or inflammable). Water is non-flammable.
2 – Reaction with acid: ability to react with acid. Limestone (chalk) reacts with acid producing bubbles of gas. 4

5. Elements 5

6. The periodic table has 7 periods and 18 families.
Each row in the periodic table is known as Periods. The columns, which consist of elements having similar chemical properties, are known as Groups or Families.
The periodic table has 7 periods and 18 families. 6

7. METALS NONMETALS METALLOIDS
Shine, usually grey (except gold and copper), and solid (except mercury). They are good conductors of heat & electricity. Can be hammered into sheets without breaking.
Dull, different colours , solid, gases, or liquid. Not good conductors. Easily broken.
An element having both metallic and nonmetallic properties. They are usually good semiconductors
(web.buddyproject.org/.../web017/ images/periodic%20table.JPG) 7

8. Examples of chemical groups (families)
Noble gases
Alkali metals
Halogens 8

9. ATOM
Atom is the smallest amount of an element

10. Atomic model
Electrons
nucleus with
Protons
Neutrons 10

11. 0(almost 2000 times lighter than proton or neutron)
SUBATOMIC PARTICLES
Particle
Charge
Mass
proton p+
positive charge 1
neutron n
no charge 1
0(almost 2000 times lighter than proton or neutron)
electron e-
negative charge 11

12. Atomic Number
Is the number of protons in an atom. by association, it’s also the number of electrons, since atoms are neutral (charge zero) 12

13. 2.4 13

14. Practice questions
State the number of protons for atoms of each of the following: 1. Nitrogen a) 5 protons b) 7 protons c) 14 protons 2. Sulfur a) 32 protons b) 16 protons c) 6 protons 3. Barium a) 137 protons b) 81 protons c) 56 protons 14

15. Answers
State the number of protons for atoms of each of the following: 1. Nitrogen b) 7 protons 2. Sulfur b) 16 protons 3. Barium c) 56 protons 15

16. Mass Number (different from atomic mass)
Mass number = number of protons + number of neutrons 16

17. Atomic number and atomic mass in the Periodic Table11 Na
22.99
Atomic Number
Protons =11
Electrons =11
Protons +neutrons =22.9
(round off the number to 23)
Neutrons =23-11=12
Symbol
Atomic Mass 17

18. Standard atomic notation
Atomic number = number of protons in nucleus
Mass number = number of protons + number of neutrons
= atomic number + number of neutrons
Mass Number Cl 35 17
Element Symbol
Atomic Number
17 protons
17 electrons
18 neutrons (= ) 18

19. Subatomic Particles in Some Atoms
O P Zn
8 p p p+
8 n 16 n 35 n
8 e e e- 19

20. So far: numbers of subatomic particles Now: arrangement20 20

21. Protons and neutrons: nucleus Electrons
The circles are NOT orbits. The electrons are NOT moving around the nucleus along the circles, like planets around the sun. It is impossible to know how an electron is actually moving in an atom .
Instead, the circles represents regions called orbitals (or shells) with different energy levels. The two electrons on the circle closest to the nucleus have the lowest energy and the eight electrons on the next circle have a higher energy. 21 21

22. 2-8-8 rule*
Building in which next floor up can only be filled if the lower floor is filled
* The maximum number of electrons that can occupy each shell has been determined for the 20 first elements 22 22

23. ELECTRON ORBITALS
Electrons are arranged in Energy Shells/ or Valence Shells around the nucleus of an atom.
first shell a maximum of 2 electrons
second shell a maximum of 8 electrons
third shell a maximum of 8 electrons

24. BOHR - RUTHERFORD DIAGRAMS
Bohr – Rutherford diagrams are simple drawings that show the numbers and locations of protons, neutrons and electrons in an atom (or ion). o o
Nitrogen
7p+
7n0 14 o o o o N 7 o

25. BOHR - RUTHERFORD DIAGRAMS
Draw the Bohr - Rutherford diagrams for the atoms of the following elements: Oxygen and Chlorine o o 16 35 O Cl a) b) o o 8 17 o o o o o o o o o
17 p+
18 no o o o o o
8 p+
8n0 o o o o o o

26. SUMMARY The Atomic Number of an atom = number of
protons in the nucleus.
The Mass Number of an atom = number of
Protons + Neutrons in the nucleus.
Atomic Mass = mass of protons and neutrons and electrons of the atom
The number of Protons = Number of Electrons.
Electrons are located around the nucleus in energy shells.
Each shell can only carry a set number of electrons.

27. ATOMIC STRUCTURE MODELS
There are several ways to represent the atomic structure of an element or compound:
1. Bohr - Rutherford Diagrams
2. Electronic Configuration

28. ELECTRONIC CONFIGURATION
With electronic configuration elements are represented numerically by the number of electrons in their shells and number of shells. For example;
Nitrogen
configuration = 2 , 5 14 N
2 in 1st shell
5 in 2nd shell
= 7 7

29. ELECTRONIC CONFIGURATION
Write the electronic configuration for the following elements; 40 23 16 Ca Na a) b) c) O 8 11 20
2,8,8,2
2,8,1
2,6
Notice the difference in location of atomic number, symbol 35 28 11 Cl Si B d) e) f) 17 5 14
2,8,7
2,8,4
2,3 29

30. Ion (charged atom)

31. Ions (charged atom)

32. Formation of Ionic Compounds

33. Ionic Compound (metal + non metal)
Write down the name of the first element;
Write down the name of second element and add “IDE”.
e.g. Magnesium + oxygen magnesium oxide
BaCl2
barium chloride
K2O
potassium oxide

34. BaCl2
K2O