Periodic Table and Periodicity

The structure of the Periodic Table

GROUPSGroup numbers indicatethe amount of valence electrons in the relevant element’s atom.

Valence electrons

Electrons that occur in the highest (outer) energy level of the atom.

PERIODSThere are seven periods on the

Periodic Table.

The period number will indicate the amount of energy levels that an atom consist of.

Ois in group 6, so has 6 valence electrons.

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3s24p4Group

6

Period 3

Cais in group 2, so

has 2 valence electrons.

4s2 Group 2

Period 4

Recurring pattern of physical and chemical

properties as you move across the Periodic Table.

Periodicity

The elements of the same group have

similar properties. These properties differ

from left to right.Periodic Law

Atomic Radius

Distance from the nucleus and the outermost stable electron orbital.

Atomic Radius

Decreases

• Atomic number increases from left to right.

• This means the nuclear charge increases.• The electrostatic forces between the

nucleus and electrons increase, pulling electrons closer.

• Thereby decreasing the atomic radius.

Increases

• The main energy levels increase by one as you move down one period, thus taking up more space.

• The valence electrons are further away from the core.

• The electrons from the inner orbitals shield the outer electrons,

• Which weakens the attractive forces of the core on the outer electrons.

Melting point and boiling point

MetalsNon-metalsIn groups

DensityMetals

Non-metals

Ionisation energy

Energy required to remove the electron from an atom in the gaseous state.

Ionisation energy

Factors that influence ionisation energy:

Nuclear chargeAtomic radius

Electron repulsion

Successive ionisation energies

• When the first electron is removed, the nuclear charge increases, holding the remaining electrons tighter.

• To remove the next electron requires more energy.

The change in energy when an electron is added to a neutral atom or ion in the gaseous phase.

Electron affinity

Electron affinity increases from left to right.

Decreases from top to bottom.

The amount of energy released when an electron is added to atoms in the ground state.

Electronegativity

Pauling Scale

OLIVIER, A. : Physical Sciences Theory and Workbook Book 2 Chemistry, Grade 10; AmaniYah .Slide 1: http://sciencenotes.org/wp-content/uploads/2014/10/Cat_Periodic_Table2_Rainbow.png Slide 3, 4 + 6: http://sciencenotes.org/wp-content/uploads/2014/11/periodic-table-printable.png Slide 5: http://www.animateit.net/data/media/july2012/animated-gifs-atoms-28.gif Slide 10 + 12, 13: https://sisu.ut.ee/sites/default/files/styles/os_files_xxlarge/public/keemilineside/files/atomic_radius_pt.jpg?itok=hpF3FSanSlide 14: http://www.docbrown.info/page07/periodgraphs/image001edit20.gifSlide 15: http://www.docbrown.info/page07/periodgraphs/image006edit20.gif Slide 17: http://images.slideplayer.com/2/683854/slides/slide_5.jpg Slide 18: http://images.slideplayer.com/2/683854/slides/slide_5.jpg Slide 19: http://www.blobs.org/science/chemistry/na.gif Slide 23: http://www.angelo.edu/faculty/kboudrea/periodic/trends_electron_affinity_fig1.gif Slide 26: http://graphshamaddox.weebly.com/uploads/1/4/2/5/14254235/3367545_orig.png Slide 27: http://www.dynamicscience.com.au/tester/solutions1/chemistry/electronegativity4.gif