1. The Fundamental Ideas in Chemistry
The Periodic Table

2. What do I need to know? Must
Recall that all substances are made of atoms
Should
Explain that an element is a substance made of only one sort of atom.
Could
Describe the location of different elements within the periodic table

3. Atoms and Elements
All substances are made of ______. A substance that is made of only one sort of atom is called an _________. There are about 100 different _________ which are shown in the __________.
[element, periodic table, elements, atoms]

4. Examination question

5. The periodic table of the elements
In the periodic table elements that have similar properties are found in the same vertical column or “GROUP”.
These all have the same number of OUTER ELECTRONS.
We call the rows in the periodic table “PERIODS” and elements are arranged in order of increasing ATOMIC NUMBER
Each element has a different chemical symbol

6. Periodic table
As you can see MOST elements are metals

7. Test your knowledge
Elements are arranged in the ________ ______ according to their ________ ________. The _________ contain elements with similar ___________. [properties, periodic table, groups, atomic number]

8. Examination question

9. Chemical symbols
It is important that the first letter of a chemical symbol is a capital letter and the second letter (if there is one) must be lowercase eg Ca not CA. Here are some to learn.
Hydrogen H
Magnesium Mg
Zinc Zn
Lithium Li
Calcium Ca
Carbon C
Sodium Na
Iron Fe
Nitrogen N
Potassium K
Copper Cu
Oxygen O
Sulphur S
Chlorine Cl
Neon Ne
Argon Ar
Lead Pb
Silicon Si

10. Summary Recall that all substances are made of atoms
Explain that an element is a substance made of only one sort of atom.
Describe the location of different elements within the periodic table

11. The Fundamental Ideas in Chemistry – Lesson 2
Atomic structure

12. What do I need to know? Must
Recall that atoms of each element are represented by a chemical symbol
Should
Describe the composition of an atom and the properties of sub-atomic particles
Could
Explain that atoms of a particular element all have the same number of protons.

13. Test Your Knowledge Write down the chemical symbol Iron Oxygen Sulphur
Copper
Sodium
Write down the name of these elements Mg N Li K Ne

14. Structure of the atom
An atom is made up of protons, neutrons and electrons.
The protons are positively charged and are found in the nucleus
The neutrons are neutral and are found in the nucleus
The electrons are negatively charged and are found orbiting the nucleus.

16. Test your knowledge
The particles in an atom are… , , and Niels Bohr discovered…

17. Test your knowledge
The particles in an atom are… protons neutrons , and electrons Niels Bohr discovered that electrons that orbit the nucleus have different energy levels.

20. Summary
Recall that atoms of each element are represented by a chemical symbol
Describe the composition of an atom and the properties of sub-atomic particles
Explain that atoms of a particular element all have the same number of protons.

21. Fundamental Ideas C1.1
Atomic structure part 2

22. What do I need to know?
Must Recall that atoms are made up of protons neutrons and electrons. Should Explain that atoms of an element have the same number of protons and electrons. Could Use the mass number to work out how many neutrons there are in an atom.

23. How many particles MASS NUMBER
ATOMIC NUMBER – elements are arranged in order of this

24. How many particles Number of neutrons = MASS NUMBER – ATOMIC NUMBER
= 12 – 6
= 6
This is the number of protons (6)
This is the number of electrons (6)

25. We can also get Carbon -13
How many protons, neutrons and electrons does carbon-13 have?
Neutrons = mass number – atomic number
=13 – 6
= 7 neutrons
Atomic number = 6
so 6 protons and 6 electrons.

26. Definitions
Atomic number – number of protons in the atom which is characteristic of the element. It is also the number of electrons in the atom.
Mass number – the total number of protons + neutrons
Number of neutrons can be different even for the same element. These are called ISOTOPES

27. Test yourself
Use a periodic table to work out how many protons, neutrons and electrons the following elements have?
Element
Number of protons
Number of neutrons
Number of electrons
Magnesium
Carbon
Hydrogen
Fluorine
Neon

28. Examination question

29. Examination question

30. Examination Question

31. Summary
Must Recall that atoms are made up of protons neutrons and electrons. Should Explain that atoms of an element have the same number of protons and electrons. Could Use the mass number to work out how many neutrons there are in an atom.

32. The Fundamental Ideas in Chemistry
Electron Shells

33. What do I need to know? Must
State that electrons occupy different energy levels
Should
Explain that electrons occupy the lowest available energy levels
Could
Draw the electron arrangement for an element

34. Electronic structure
Electrons occupy particular _________levels. The electrons in an atom occupy the ______ available energy levels (closest to the _______). [nucleus, energy, lowest]

35. Numbers of electrons
Successive levels hold a maximum of:
2, 8, 8, 18

36. To work out which energy level
Look at the atomic number on the periodic table to work out HOW MANY ELECTRONS the element has.
Put up to 2 of these in the first level
Put up to 8 of these in the next level
Put up to 8 of these in the next level.
The total number must be the same as the number of electrons the element has.

37. Electronic structure examples
Magnesium has 12 electrons
2 in the first
8 in the second
2 in the third
2,8,2 = 12 overall

38. Electronic structure examples
Chlorine has 17 electrons
2 in the first
8 in the second
7 in the third
2,8,7 = 17 overall

39. Electronic structure examples
Hydrogen has 1 electron
1 in the first
1 = 1 overall

40. Drawing diagrams
We show electronic structure in circles around the atom with the lowest energy nearest the nucleus

41. Electrons and reactions
The number of electrons in the outer shell gives an element its reactivity.
For example one outer electron is VERY reactive for example Li, Na, K, Rb.
A FULL shell is called a NOBLE GAS. These are VERY UNREACTIVE eg He, Ne, Ar, Kr, Xe.

42. Noble gases
Unreactive gases with full outer shell can be used inside light bulbs because they do not react with the filament.
If we used air only then the oxygen in the air would react with the filament and burn it.

43. Examination questions

44. Li, Na, K – anything in common?

45. Alkali metals We call the metals in group 1 the “alkali metals”
They are very reactive because they all have ONE outer electron.
When alkali metals react with water it is very violent. They are more reactive as you go down the group.

46. [electrons, energy level, full, reacts, group,
Test your knowledge
Elements in the same_______ have similar reactions because they have the same number of _________in their outer _______ ________. The number of outer electrons determines how an atom ______. Atoms with ____outer energy levels are unreactive. These are called the _____ _____. They are unreactive because their atoms have _______ arrangements of electrons .
[electrons, energy level, full, reacts, group,
noble gases, stable]

47. Summary
Recall that elements in the same group have the same number of electrons in their outer energy level
Explain that the outer energy level electrons give an element its properties
Describe how the number of outer electrons can mean that a substance is very reactive or not reactive at all

48. The Fundamental Ideas in Chemistry
Elements and compounds

49. What do I need to know?
Must State that when elements react their atoms join with other atoms to form compounds Should Describe how bonding involves giving, taking or sharing electrons. Could Explain that compounds involving metals and non-metals involve ionic bonding and compounds of only non-metals involve covalent bonding.

50. Definitions An element is a substance made from only ONE KIND OF ATOM
A compound is a substance made from one or more types of atoms CHEMICALLY BONDED TOGETHER
A mixture is a number of different elements or compounds NOT BONDED TOGETHER.

51. Examination questions

54. Test your knowledge
When elements react, their atoms join with other atoms to form________. This involves giving, taking or sharing _________ to form _____ or ________. Compounds have different __________ to the elements that made them. [ions, compounds, properties, molecules, electrons]

55. Why bond?
Chemical elements bond in order to gain a full outer shell of electrons.
This makes them stable
They can do this by giving electrons away, gaining electrons or sharing electrons.

56. Ionic bonding
This type of bonding generally happens between METALS and NON-METALS
It involves the outer electrons of the atoms.
Electrons are transferred between the two atoms
Ions are formed which are attracted to each other.

57. Na gives Cl an electron we call this ionic bonding
Ionic bonding forms IONS which have positive and negative charges and attract each other

58. Covalent bonding
This type of bonding generally occurs between non-metals
It involves sharing electrons to gain a full shell and therefore become stable.

59. Two H atoms share an electron with O we call this covalent bonding
Covalent bonding forms MOLECULES

60. Test your knowledge
Ionic bonding
Compounds formed from _______ and non-metals consist of positive and negative ____. An _________ is completely transferred.
Covalent bonding
Compounds formed from _________ and non-metals consist of ________. Electrons are _______.
[electron, metals, ions, molecules, non-metals, shared]

63. Summary
State that when elements react their atoms join with other atoms to form compounds Describe how bonding involves giving, taking or sharing electrons. Explain that compounds involving metals and non-metals involve ionic bonding and compounds of only non-metals involve covalent bonding.

64. The Fundamental Ideas in Chemistry
Chemical equations

65. What do I need to know?
Must Recall that chemical reactions can be represented by word equations or symbol equations. Should Describe how no atoms are lost or made during a chemical reaction so the mass of the products equals the mass of the reactants. Could Calculate the mass of a reactant or product from information about the masses of the other reactants and products in the reaction.

66. Word equations
A word equation describes a reaction, for example burning lithium in air. lithium + oxygen  lithium oxide Can you write word equations for the following…

67. Word equations The reaction between potassium and oxygen
The reaction between lithium and water
The reaction between calcium and oxygen
The reaction between rubidium and water

68. Word equations The reaction between potassium and oxygen
potassium + oxygen  potassium oxide
The reaction between lithium and water
lithium + water  lithium hydroxide + hydrogen
The reaction between calcium and oxygen
calcium + oxygen  calcium oxide
The reaction between rubidium and water
rubidium + water  rubidium hydroxide + hydrogen

70. Symbol equations
Symbol equations use chemical symbols and are “balanced” to show the actual number of atoms used. For example Li + H2O  LiOH + ½ H2 is lithium + water  lithium hydroxide + hydrogen Note that we don’t generally include the numbers in the word equation.

72. Change these symbol equations into word equations
K + H2O  KOH + ½ H2 2Mg + O2  2MgO Na + H2O  NaOH + ½ H2 Ca + 2H2O  Ca(OH)2 + H2 4Fe + 3O2  2Fe2O3

73. Change these symbol equations into word equations
K + H2O  KOH + ½ H2 Potassium + water  potassium hydroxide + hydrogen 2Mg + O2  2MgO Magnesium + oxygen  magnesium hydroxide Na + H2O  NaOH + ½ H2 Sodium + water  sodium hydroxide + hydrogen Ca + 2H2O  Ca(OH)2 + H2 Calcium + water  calcium hydroxide + hydrogen 4Fe + 3O2  2Fe2O3 Iron + oxygen  iron oxide

74. Balancing equations
Symbol equations need to be balanced because the number of atoms reacting at the start MUST be the same as the number of atoms in the products.
An unbalanced reaction cannot properly represent a reaction because there is an imbalance in the number of atoms in the reactants and products.
The mass of reactants MUST also be the same as the mass of products.

75. Is it balanced?
Ca + H2O  Ca(OH)2 + H2 Mg + O2  MgO Li + H2O  LiOH + ½ H2 C6H12 + 9O2  6CO2 + 6H2O

76. Is it balanced?
Ca + H2O  Ca(OH)2 + H2 NO! Mg + O2  MgO Li + H2O  LiOH + ½ H2 YES! C6H12 + 9O2  6CO2 + 6H2O

78. Calculating masses
We can predict the mass of product from the mass of reactants because we know that mass is conserved. Example 2Mg + O2  2MgO If 24 g Mg reacts completely with 16g of O2 what mass of MgO is made? = 40 g

79. Calculating masses
2Li + 2H2O  2LiOH + H2 A piece of lithium weighing 7g is allowed to react with 18g of water. We collect 1g of hydrogen gas in the test tube. How much lithium hydroxide has been made? – 1 = 24 g

80. Calculating masses
C6H12 + 9O2  6CO2 + 6H2O If 84g of hexane (C6H12) are burnt completely in 288g of oxygen we measure 108g of water produced. How much carbon dioxide was given off? – 108 = 264 g

81. How to balance
When we balance equations we do not change the small (susbscript numbers)
eg Ca(OH)2 because this would change the compound itself
We do change the LARGE number in front of the compound
Eg 2Ca(OH)2 because this changes the amount.

83. Summary
Recall that chemical reactions can be represented by word equations or symbol equations. Describe how no atoms are lost or made during a chemical reaction so the mass of the products equals the mass of the reactants. Calculate the mass of a reactant or product from information about the masses of the other reactants and products in the reaction.