STARTER Complete the word wheel. Write the keywords in a short paragraph but they must be in the order of the word wheel. Electrons Atomic Mass Protons Isotopes Neutrons You can start anywhere on the word wheel.

Learning Outcomes 1.13 - understand that the Periodic Table is an arrangement of elements in order of atomic number 1.14 - deduce the electronic configurations of the first 20 elements from their positions in the Periodic Table 1.15 - deduce the number of outer electrons in a main group element from its position in the Periodic Table.

On Mini - white boards What are the number of protons, neutrons and electrons for: Hydrogen. Boron. Sodium.

Hydrogen Atom 1 Protons 0 Neutrons 1 Electron

Boron Atom 5 Protons 6 Neutrons 5 Electron

Sodium Atom 11 Protons 12 Neutrons 11 Electron

x x x 1st shell holds up to 2 electrons HELIUM HYDROGEN 2p 2n 1p x HYDROGEN 1 proton, 1 electron HELIUM 2 protons, 2 electrons, 2 neutrons

Rules for filling shells In HELIUM, the outer shell is FULL. This shell only holds up to 2 electrons. We need to start on a new shell. This holds up to 8 electrons. Try to draw the atoms for lithium up to neon.

x x x x x LITHIUM BERYLLIUM 3 protons, 3 electrons, 4 neutrons

x x x x x x x x x x x BORON CARBON 5 protons, 5 electrons, 6 neutrons

x x x x x x x x x x x x x x x OXYGEN NITROGEN 7p 7n 8p 8n x x x x x x x x OXYGEN 8 protons, 8 electrons, 8 neutrons NITROGEN 7 protons, 7 electrons, 7 neutrons

x x x x x x x x x x x x x x x x x x x NEON FLUORINE 9p 10n 10p 10n x x x x x x x x x x x NEON 10 protons, 10 electrons, 10 neutrons FLUORINE 9 protons, 9 electrons, 10 neutrons

Rules for filling shells In NEON, the outer shell is FULL. We need to start on a new shell. This also holds 8 electrons. Try to draw the atoms for sodium up to calcium.

Have a look at this table –what does it tell us about each element Have a look at this table –what does it tell us about each element? Must refer to periodic table Element no. Symbol Shell1 Shell2 Shell3 Shell4 1 H 2 He 3 Li 4 Be 5 B 6 C 7 N 8 O 9 Fl 10 Ne Valence electrons – group number Number of shells – period number

Question! Have a look at the diagram on the right… What do you think these numbers mean? Discuss in pairs.

Electron configuration Work out the numeric format for the following elements: Carbon Sodium Flourine Magnesium Argon

Answers Carbon: 2,4 Sodium: 2,8,1 Fluorine: 2,7 Magnesium: 2,8,2 Argon: 2,8,8

Complete worksheet Periodic table basics worksheet

Group Task As a class: Can you arrange yourselves to show the Atomic structure of NITROGEN including the correct electrons in each shell? You have 3 minutes!

Can you find the four mistakes and correct them? The proton number of an element tells you how many protons or neutrons each atom has. The first electron shell of an atom can only hold four electrons. The second and third shells can hold up to 9 electrons each. An electron shell doesn’t have to be full before you start adding electrons to the next shell up.

Octet rule All atoms want to have a full outer shell like neon and Argon etc. To do this Atoms gain or loose electrons

Task For the following state whether it’ll be easier to gain or loose electrons Eg its easier to gain 3 rather than loosing 5

Gain? Lose?

Lose 2 electrons

Gain? Lose?

Gain 2 electrons

Gain? Lose?

Gain 1 electron

Gain? Lose?

Gain 3 electrons

Gain? Lose?

Lose 3 electrons

Gain? Lose?

Lose or Gain 1 electron

Draw the electron configuration of the following Sodium ion Chlorine ion Nitrogen ion Oxygen ion Magnesium ion Boron ion Note: original electrons in dots and new electrons in crosses