Atomic structure - PowerPoint Presentation

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Atomic structureSlide2
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Application

Property

Metal

Non-metal

Colour

Metals can be polished to a high gloss. Mercury is used in the manufacture of mirrors

Some paints which are used as interior paints are lustreless.

Malleability/brittle

Metals can be rolled out into very thin sheets and wires e.g. aluminium foil and iron wire

Although diamonds are the hardest known substance, they are very brittle and will shatter when hit with a hammer.

Heat conductivity

Tin mug will burn your lips while drinking hot coffee from it. Cooking utensils are made from metals.

A porcelain mug will not burn your lips while drinking hot coffee. Ceramic tiles are used as insulation for the space shuttle against over heating when returning to earth.

Electrical conductivity

All metals are good conductors of electricity. Copper is a better conductor of electricity than most other metals, this is why copper is used in electric cables.

Porcelain and ceramic are mostly composed of silicon. They are used as insulators.

Metallic sound

Many musical instruments like trumpets, flutes and bugles are made of copper or nickel or silver.

Used to supress noise, because they are poor conductors of sound.Slide4

Each statement below describes an element, write down the name and symbol for each element described

.

Metal used in thermometers

Metal used to make window frames.

Element with 3 protons

Yellow metal used to make jewellery

Gas needed for breathing

Metal used in electric circuits

The two elements that make up table salt.

Element with 16 protons.Slide5

The diagram below is of a simple neutral carbon atom.Slide6

The nucleus of the atom contains protons(+) neutrons(0)

The atomic number equals the number of protons and the number of electrons in a neutral atom.

Group I metals:

Are very reactive, there is only 1 electron in the outer most energy level, therefore it has 1 valence electron – it readily gives 1 electron away.

Group II metals:

Is reactive, there are 2 electrons in the outermost energy level, therefore it has 2 valence electrons – has to give 2 electrons away.

Group III metals:

Is less reactive, has 3 electrons in the outermost energy level – gives 3 electrons away.

Metals give away electrons therefore they form positive ions also known as

cations

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Group VI - non metals

They have 6 valence electrons, they gain 2 electrons so they have a

valency

of 2 (8-group number)

Group VII – halogens

All halogens are diatomic, they have 7 valence electrons, therefore they gain 1 electron so they have a

valency

of 1Slide7

Non metals accept electrons, therefore forming negative ions, also known as anions.

Valence electrons:

Is the number of electrons in the outermost energy level

Valency

:

Is the number of electrons that an atom must lose or gain or share in order to achieve a perfect octet in the outer most energy levels.

The inner most energy level can only accommodate 2 electrons as it is so small, all other energy levels can accommodate a maximum of 8 electrons per energy level.

For example:

Hydrogen has an atomic number of 1 so it only has 1 proton in the nucleusSlide8
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Something interesting to remember when working with neutral atoms and having to draw them:

The number of electrons that are supposed to be in the outer most energy level is always the same as the group that that element is found in, so if for example you are drawing the atomic structure of oxygen, it is in group 6, so there needs to be 6 electrons in the outermost energy level. Oxygen is in period 2, and that indicates the number of energy levels that your drawing needs to have.Slide10

Look at picture below of oxygen:

Note the number of electrons in the outer energy level, and the number of energy levelsSlide11

Now draw the atomic structures of the following elements using your periodic tables as a reference

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He (Helium)

Na (Sodium)

C (carbon)

P (

Phosphorous

)

Remember first energy levels can accommodate a maximum of 2 electrons, other energy levels can accommodate a maximum of 8 electrons. Indicate your protons in the nucleus with a small circle with a + in it, and the neutrons with blank small circles, also give the symbol next to your drawing indicating the Mass no on top left side of your symbol and your Atomic no bottom left side of your symbol as indicated in beryllium example.