topic periodic table

8/10/2019 TOPIC Periodic Table

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TOPIC: PERIODIC TABLE

Structure of Atom

Atoms consist of electrons surrounding a nucleus that contains protons and

neutrons.Neutrons are neutral, but protons and electrons are electrically charged.

Protons have a relative charge of +1, while electrons have a relative charge of -1. The

number of protons in an atom is called its atomic number. n the periodic table, atomsare arranged in atomic number order. !lectrons are arranged in energy levels or shells,

and different energy levels can hold different numbers of electrons.

How Rutherford found Proton?

"utherford#s most famous discovery is the nucleus of the atom, specifically his

discovery of protons. The e$periment done to discover protons is %nown as the &gold foil

e$periment,& and it was performed by 'ans (eiger and !rnest )arsden in 1**, under"utherford#s supervision. The e$periment involved shooting a beam of particles at a

narrow piece of foil made of gold in order to see how the atoms scattered. rom this

e$periment, "utherford came to the conclusion that atoms must have a positive mass

centered in their middle. n 1*, "utherford proposed the name &proton& for the

particles that create this positive mass.

"ead more/http/00www.ehow.com0info2345356rutherford-discoveries.html7

Date :

Objective of lesson:

Pupils should be able to/

8 Describe the structure of atoms (Rutherford)

8 Relate structure to the first twenty elements of the Periodic Table

8 Describe trends in groups and periods

Watch Rutherford activity right here.
http://www.ehow.com/info_8356367_rutherford-discoveries.htmlhttp://var/www/apps/conversion/tmp/scratch_4/Periodic%20Table/Rutherford%20Gold%20Foil%20Experiment%20-%20Backstage%20Science.mp4http://var/www/apps/conversion/tmp/scratch_4/Periodic%20Table/Rutherford%20Gold%20Foil%20Experiment%20-%20Backstage%20Science.mp4http://www.ehow.com/info_8356367_rutherford-discoveries.html


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Recognise the symbols for the first ! elements "nd "rr"nge the first ! elements

into the Periodic #"ble$

Play card game/

1. Total of cards / 1 different information $ elements 9 cards

. n one group will receive 33 cards randomly.

3. n rotation formation, barter system will be use to e$change your card, until

your group able to collect about 3 elements with correct information 1 info

for each elements7

%now the b"sic structure of "n "tom$

or :ithium atom, number of atom is 3. f the number of proton is 3+, the number of

electron also 3-. :ithium :i7 is drawn as below;


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Recognise Periods "nd &rou's$

Periods

"ows of elements are called periods. The period number of an element signifies the

highest une$cited energy level for an electron in that element. The number of elements

in a period increases as you move down the periodic table because there are more

sublevels per level as the energy level of the atom increases.

&rou's

@olumns of elements help define element groups. !lements within a group share

several common properties. (roups are elements have the same outer electron

arrangement. The outer electrons are called valence electrons.


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&rou' +: Al,"li -et"l Pro'erties

The al%ali metals e$hibit many of the physical properties common to metals, although

their densities are lower than those of other metals. Al%ali metals have one electron in

their outer shell, which is loosely bound. This gives them the largest atomic radii of the

elements in their respective periods. Their low ioniBation energies result in their metallic

properties and high reactivity. An al%ali metal can easily lose its valence electron to form

the univalent cation. Al%ali metals have low electro negativities. They react readily with

nonmetals, particularly halogens.

&rou' : Al,"line ."rth Pro'erties

The al%aline earths possess many of the characteristic properties of metals. Al%aline

earths have low electron affinities and low electro negativities. As with the al%ali metals,

the properties depend on the ease with which electrons are lost. The al%aline earths

have two electrons in the outer shell. They have smaller atomic radii than the al%ali

metals. The two valence electrons are not tightly bound to the nucleus, so the al%alineearths readily lose the electrons to form divalent cations.

&rou' /: H"logens Pro'erties

These reactive nonmetals have seven valence electrons. As a group, halogens e$hibit

highly variable physical properties. 'alogens range from solid 7 to liCuid


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Recognise the uni2ue 'osition of hydrogen$

Why ydrogen does not group together with !roup "#

"ead this article http/00www.citycollegiate.com0positionofh.htm7 then you will get the

answer. Drite its similarities and differences with (roup 1 character and properties.
http://www.citycollegiate.com/positionofh.htmhttp://www.citycollegiate.com/positionofh.htm

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