1. Grade 10 Chemistry Unit

2. LAB SAFETY View Safety Video at:
Go through safety diagram
Write the Safety Test

3. 12 13 11 10 14 9 8 4 7 6 5 2 3 1 15

4. Chapter 5 Chemicals in Action
What is chemistry?
Chemistry is the study of matter, its properties and its changes or transformations.
Matter is anything that takes up space and has mass. All types of matter have physical and chemical properties.
Physical properties include: state at room temperature (solid, liquid or gas), temperature, colour, odour, lustre, solubility and melting and boiling points.
Chemical properties include how matter reacts with: air (oxygen),acids, bases, and water

5. 5.1 Chemicals and chemical Change
There are many different types of matter that make up our world:
Pure substance – all the particles that make up this matter are the same, as a result this matter has constant properties e.g. pure water is a clear colourless substance that freezes at 0 C and boils at 100 C.
a) Pure substances can be classified as:
Elements – cannot be broken down into a simpler substance because they are made of only 1 kind of atom e.g. gold, oxygen, and mercury. These elements can be identified by a chemical symbol found on the periodic table (Au, O, Hg). Some elements consist of molecules, which are formed when 2 or more atoms join together; for example oxygen (O) occurs in nature as pairs of oxygen atoms or molecules of oxygen (O2)

6. Compounds – contain 2 or more different elements in a fixed proportion
Compounds – contain 2 or more different elements in a fixed proportion. Compounds can be identified with chemical formulas e.g. carbon dioxide (formula CO2) is a compound. Each molecule of carbon dioxide is made of 1 atom of carbon and 2 atoms of oxygen. Other examples of compounds are water (H2O), sodium chloride (NaCl or salt), and ammonia (NH3).

7. 2) Another type of matter is a mixture
2)     Another type of matter is a mixture. Mixtures are made of 2 or more pure substances and can be separated by some physical method e.g. filtering, evaporation, and magnet. E.g. salt water with sand in it. The sand can be filtered with filter paper and the salt can be separated from the water by evaporating the water.
Mixtures can be classified as:

8. Solutions – a mixture where one pure substance is dissolved in another pure substance e.g. salt in water, oxygen in air, copper in a brass loonies.
Homogeneous mixtures – a mixture that has 2 pure substances but appears to be only 1 pure substance e.g. Kool-Aid is a mixture of flavour crystals, sugar and water
Heterogeneous mixture – a mixture that has 2 or more pure substances that can be seen as separate parts or layers e.g. pizza is made of cheeses tomato sauce and pepperoni

9. Matter
Pure Substance
Mixture
Element
Compound
Solution
Heterogeneous
Homogeneous

10. Properties of Matter
A physical change is a change in the size or form of a substance, which does not change the chemical properties of the substance e.g. boiling water, or dissolving sugar in water.
A chemical change occurs when a substance changes into a new substance with different chemical properties e.g. iron rusting or burning charcoal.
The starting materials in a chemical change are called reactants and the new materials made are called products.
Iron oxygen makes rust or iron (III) oxide
Fe O makes Fe2O3
Reactants Products

11. Chemical Tests
How are chemical changes useful? Chemical changes can be used to make a new substance or identify an unknown substance. There are 4 chemical tests that can be used to identify an unknown colourless gas:
1)      Oxygen Gas – a glowing splint bursts into flames
2)     Hydrogen Gas – a lit splint will cause a small explosion or pop sound
3)     Carbon dioxide Gas – a chemical called limewater will turn from colourless to white if exposed to carbon dioxide
4) Water Vapour (Gas) – cobalt chloride paper will change from blue to pink

12. POP!!
Hydrogen Test
Oxygen Test

13. Assignment Homework : Questions 1-8 pg 175
Lab : 5.3 Testing Properties of Substances

14. 5.5 Elements and the Periodic Table
In investigation 5.3 you discovered that some substances are electrolytes and some are non electrolytes or conductors or non conductors of electricity when they are dissolved in water. What makes electrolytes different from nonelectrolytes? We can use the periodic table of Elements to help answer that question.
Periodic Table – an organized arrangement of elements that help us to explain and predict physical and chemical properties. The periodic table is generally arranges with metals toward the left side and the nonmetals towards the right side. One exception is hydrogen (H). Although it is located on the top left hand side of the periodic table it behaves mostly as a non-metal.

16. Chemical Families – elements have been grouped in columns or families
Chemical Families – elements have been grouped in columns or families. Chemical families are groups of elements in the same vertical column that have similar physical and chemical properties.
1)      Alkali metals (group 1) – include lithium (li) , sodium (Na), and potassium (K) and all are shiny, silvery metals. They form compounds that are white solids and very soluble in water
2)     Alkaline Earth Metals (group 2) – include magnesium (Mg), calcium (Ca), and barium (Ba) and all are shiny , silvery metals, but they form compounds that are not soluble in water
3)     Halogens (group 17) – include fluorine (F), chlorine (Cl), and bromine (Br) and are all poisonous elements that react easily with sodium and all other alkali metals.
4) Noble Gases (group 18) – include helium (He), and neon (Ne) and do not form compounds. The other term for the noble gases is inert gases. Inert means does not react.

18. Elements and Atomic Structure
What are atoms made of?
The Bohr-Rutherford model of the atom suggests that atoms are made of 3 types of subatomic particles
1)      protons – heavy positively charged particles that are found in a dense positive core of the atom called the nucleus. The number of protons equals the atomic # of the element on the periodic table
2)     Neutrons – neutral particles that have the same mass as a proton and are also found in the nucleus. The number of neutrons in an atom can vary. (atomic mass – atomic # on the periodic table)
3) Electrons – negatively charged particles with almost no mass that circle the nucleus at different energy levels, also called orbits or shells. Since atoms are electrically neutral that number of electrons equals the number of protons

20. The key to understanding the formation of compounds is to understand the arrangements of electrons around the nucleus. The farther away an electron is from the nucleus the more likely it is to be involved in a chemical change. The electrons in the outer orbit (valence electrons) are involved in bonding atoms together to form compounds.
Bohr diagrams are used to represent the arrangement of electrons in various orbits of an atom
---7 e-
---8 e-
---2 e- 35 17 Or Cl

21. nucleus
1st nrg level
2nd nrg level
3rd nrg level

22. Atomic Symbols     A full atomic symbol includes the symbol of the element with the atomic number at the bottom left corner and the mass number at the top left corner.     Copy Atomic Symbol Here Kr 84 36

23. Consider what might happen to the charge of a neutral atom if the outer orbit of electrons are decreased or increased in number. When this occurs the atom becomes a charged particle called an ion. Ion’s can be positively charged (caused by a loss of electrons from the outer orbit) or negatively charged (caused by a gain of electrons in the outer orbit).
The symbol of the atom changes to indicate the change in ionic charge Li becomes Li +1 when a lithium atom loses 1 electron or N becomes N –3 when a nitrogen atom gains 3 electrons.
Positive ions have the same name as their original atom, but negative ions are renamed by changing the ending of atom (ine) to (ide) e.g. fluorine (F) becomes fluoride (F-1).

24. magnesium lost 2 electronsMg
Symbol of a
Magnesium
Atom
Metal Atoms to Ions
Mg 2+
Symbol of a
Magnesium
Ion
Notice 2+ means
magnesium lost 2 electrons Mg
Atom
12p+
2e-
8e- Mg
Ion
12p+
2e-
8e- Ne
2e-
8e-
Magnesium
atom
Magnesium
Ion by losing
2 electrons
becomes
To be
like
Its nearest
Noble Gas

25. sulphur gained 2 electrons
Symbol of a
Sulpur
Atom
Nonmetal Atoms to Ions
S 2-
Symbol of a
Sulphide
Ion
Notice 2- means
sulphur gained 2 electrons
And the name changed S
Atom
16p+
6e-
2e-
8e- Ar
Atom
18p+
8e-
2e- S
Ion
16p+
8e-
2e-
Its nearest
Noble Gas
Sulphur
atom
To be like
becomes
Sulphide
ion

26. Activity 5.7 :Ionic Charges and Chemical Families (Use BLM 5.7a-c)
Homework :
Activity 5.7 :Ionic Charges and Chemical Families (Use BLM 5.7a-c)
Worksheet – Naming Ionic compounds
Worksheet - Energy Level Diagrams
Answer all questions at the bottom of each sheet when you complete activity
Answer Key

27. 5.6 How Elements Form Compounds
There are 2 types compounds :
1)      ionic compounds – formed when a metal loses 1 or more valence electrons to a non-metal, forming a positive (cation) and a negative ion (anion)which then are attracted to each other and are held together by an attraction called an ionic bond. Ionic compounds dissolve in water and separate into positive ion and negative ions. These charged particles carry electric current through the water (electrolyte)
2)     Molecular compounds are formed when 2 or more nonmetals combine together. When dissolved in water the molecules do not separate into charged particles and do not carry an electrical charge (non electrolyte)
See Dissolving Videos

28. Assignment Homework : Questions 1-4 pg 189 5.7 Conclusion : Q 3 pg 191
Ionic Compound Formation Example
Homework :
Questions 1-4 pg 189
5.7 Conclusion : Q 3 pg 191
Activity : BLM 5.5b Elements, Compounds, and the Periodic Table Crossword

29. Activity : ION Dominoes
Remove the C4- if used
Make a table to record your score
Cation/anion/formula/name
You must play an oppositely charged ion to any domino played
Record the cation and anion in your table
Play continues until one player is out of dominoes
Remaining players add up superscripts(Ca2+, N3- = -1)
Play 6 games, the player with the highest score wins
Game1/game2/game3/game4/game5/game6/total

30. 5.8 Ionic Compounds
Elements in the same chemical families form ions with similar ionic charges. Such ionic charges may also be called a valence charges or carrying capacity. Metals and non metals combine to form ionic compounds by transferring electrons from the metal to the non metal. The metal atom loses electrons and becomes positively charged and the non metal gains the electrons and becomes negatively charged. The result is a compound that is neutrally charged or the sum of the charges on the positively charged ions equals the sum of the charges on the negatively charged ions
e.g. aluminum chloride
Al loses 3 electrons = Al +3
Chorine gains 1 electron = Cl –1
To make the compound electrically neutral we would need 1 aluminum and 3 chloride ions
1aluminum(+3) + 3chlorines(-1) = 0

31. Writing Formulas for Ionic Compounds
Follow these steps: e.g. What is the formula for aluminum chloride
1)      write the symbols, with the metal first
Al Cl
2)     write the ionic charge above each symbol to indicate the stable ion that each element forms
+3 -1
3)     criss cross the charge numbers and use them as subscripts after each element. This balances the charges and makes the compound electrically neutral
Al1Cl3
1 Al (+3) and 3 Cl (-1) = 0
1(+3) (-1) = 0

33. Naming Ionic Compounds
Just as in the chemical formula the name of the metal is first followed by the name of the non-metal. However the ending of the non-metal changes to “ide”
A compound made of aluminum and chlorine AlCl3 is called aluminum chloride
Some metals can have 2 or more carrying capacities. These compounds are named the same way as other ionic compounds except a roman numeral is used after the metal to identify which ionic charge is used the metal in the formula
e.g.Copper has 2 carrying capacities Cu +1 and Cu +2
When copper combines with oxygen we must identify which positive ion is being used.
Copper (I) Oxide - Cu2O
Copper (II) Oxide – CuO * notice that we have reduced from Cu2O2 to CuO because this is still electrically neutral

34. Assignment
Homework : Q 1-10 pg 195
BLM 5.8

35. 5.9 Polyatomic Compounds
Some compounds like calcium carbonate and copper (II) sulphate do not end in “ide” like other ionic compounds. Why?
Such compounds are pure substances that involve a metal ion and a polyatomic or complex ion.
Polyatomic ions are groups of atoms that tend to stay together and carry an overall charge. E.g. sulphate ion is SO4 -2

36. Writing Formulas for Polyatomic Compounds
We use the same steps that we learned in section 5.8
What is the formula for copper (II) sulphate
1)      write the symbols for the metal and the polyatomic group
Cu SO4
2)     write the ionic charges
+2 -2
Cu SO4
3)     Criss Cross and reduce the subscripts to their simplest terms if possible. Brackets may be needed if there is 2 or more polyatomic ions. Never change the subscript of the polyatomic group.
Cu2 SO42 = Cu2 (SO4)2 = Cu SO4

37. Naming Polyatomic Compounds
The name of the above compound is Copper (II) Sulphate
The name is simply the name of the metal (use a roman numeral if the metal has more than 1 positive charge) and the name of the polyatomic ion . Both can be found on the periodic table by looking them up.

38. Assignment
BLM 5.9
Homework : Q 1-7 pg 198
Worksheet-Polyatomic ions,

39. Molecular Compounds (COVALENT)
Most of the compounds you encounter each day do not contain ions. Most everyday compounds are molecular or made of only nonmetals. E.g. sugar, plastic and water
Molecular compounds are formed when 2 non-metal atoms share their outer electrons to fill each others outer orbits. This sharing of electrons results in a covalent bond that holds the atoms together as a molecule.
Atoms become more stable when their outer orbit is full
Some elements exist as molecules rather than atoms for this reason
I2 , Br2 , Cl2 , F2 , O2 , N2 , H2

41. simplify Writing Formulas for Molecular Compounds
The method is similar to writing ionic formulas. The number of electrons an atom wants to share to become stable is a clue to the number of covalent bonds that atom will form. The combining capacity of a non-metal is a measure of the number of covalent bonds. These combining capacities are listed below : H
C N O F
Si P S Cl
As Se Br I
What is the formula for the compound made of carbon and oxygen?
4 2
C O = C2O4 = CO2
simplify

42. Naming Molecular Compounds
Some molecular compounds have common names like :
H2O = water
NH3 = ammonia
CH4 = methane
H2O2 = Hydrogen Peroxide
O3 = Ozone
Or they can be named using prefixes which represent the number of each atom in the compound
H2O = di Hydrogen monOxide
NH3 = Nitrogen triHydride
CH4 = Carbon tetraHydride

43. Tri =3 Hept(a) = 7 Tetra = 4 Oct(a) = 8 Pent(a) = 5 Non(a) = 9
Notice the second part of the name still ends in “ide” like many of the ionic compounds. You must know the following prefixes:
Mon(o) = 1 (optional on first name not the second)
Di =2 Hex(a) = 6
Tri =3 Hept(a) = 7
Tetra = 4 Oct(a) = 8
Pent(a) = 5 Non(a) = 9
Dec(a) = 10
e.g.
CO2 is carbon dioxide P2 H4 is Diphosphorous Tetrahydride
CO is carbon monoxide SiO2 is silicon dioxide
P3Br8 = = Tetrasulfur nonoxide
N2O2 = = HeptaSelenium DecaIodie

44. Assignment Worksheet – Molecular Compounds Homework : 1-6 pg 204
BLM 5.11

45. References
This power point presentation was created by Terry Sproat used with permission