CHEMICAL PATTERNS
Module 3
By the end of this lesson I should be able to……..
Predict the electron arrangement in atoms using the periodic table. Appreciate that atoms like to have full orbits of electrons if they are to be stable. Understand the link between electron arrangement and reactivity. Know which elements are the halogens. Know the properties of the halogens
Using Power Point
If it is written in white – it should be in my exercise book!
If it is written in red – it need not be in my exercise book.
The Atom
The Atom
Arranging electrons
Element Atomic no. Electron arrangement Periodic table group
Li Na K Fl Cl Br Ne Ar Kr
Arranging electrons
Element Atomic no. Electron arrangement Periodic table group
Li Na K Fl Cl Br Ne Ar Kr
3
Arranging electrons
Element Atomic no. Electron arrangement Periodic table group
Li Na K Fl Cl Br Ne Ar Kr
3
2,1
1
Arranging electrons
Element Atomic no. Electron arrangement Periodic table group
Li Na K Fl Cl Br Ne Ar Kr
3 11
2,1 2,8,1
1
Arranging electrons
Element Atomic no. Electron arrangement Periodic table group
Li Na K Fl Cl Br Ne Ar Kr
3 11 19
2,1 2,8,1
1
Arranging electrons
Element Atomic no. Electron arrangement Periodic table group
Li Na K Fl Cl Br Ne Ar Kr
3 11 19 9 17 35 10 18
2,1 2,8,1
1
Groups in the Periodic Table
Elements in the same group always have the same number of electrons in their outer orbitals. All members of Group 1, the Alkali Metals, have 1 electron in their outer shell.
Groups in the Periodic Table
All members of Group 2 have 2 electrons in their outer shell. All members of Group 7, the halogens, have 7 electrons in their outer shell.
Groups in the Periodic Table
All members of Group 8, the Noble Gases, have 8 electrons in their outer shell.
Stable (happy) atoms!
Atoms will always try and get full outer shells of electrons. If the outer shell is full the atom is stable! Atoms will always try and react in order to end up with a full outer shell!
Group 1 metals will react in order to lose their outer electron. This means they will have a positive charge after they have reacted. Because the lose one negative charge they are left positive overall.
Group 7 halogens will react in order to gain an extra outer electron. This means they will have a negative charge after they have reacted. Because the gain one negative charge they are left negative overall.
Move into room 143!
Looking at the HALOGENS!
The Halogens
Element Symbol Atomic no. State at room temperature Boiling point OC
Fluorine
Fl
9
Fluorine
A very pale yellow gas Incredibly corrosive – it can not be kept in a glass jar because it would rot the glass. These containers of fluorine are made of quartz.
The Halogens
Element Symbol Atomic no. State at room temperature Boiling point OC
Fluorine
Fl
9
pale yellow - 188 gas
The Halogens
Element Symbol Atomic no. State at room temperature Boiling point OC
Fluorine
Fl
9 17
pale yellow - 188 gas
Chlorine Cl
Chlorine
A green gas Very poisonous Used in the First World War in the gas attacks that blinded and killed thousands of soldiers (used by both the Germans and the British)
The Halogens
Element Symbol Atomic no. State at room temperature Boiling point OC
Fluorine
Fl
9 17
Chlorine Cl
pale yellow - 188 gas Green gas - 35
The Halogens
Element Symbol Atomic no. State at room temperature Boiling point OC
Fluorine
Fl
9 17 35
Chlorine Cl
pale yellow - 188 gas Green gas - 35
Bromine Br
Bromine
A brown liquid Will boil and turn into a gas with very little heating. Very poisonous – can dissolve your lungs. Said to be put in the tea of troops to supress sexual desires!
The Halogens
Element Symbol Atomic no. State at room temperature Boiling point OC
Fluorine
Fl
9 17
Chlorine Cl
pale yellow gas green gas
- 188 - 35
Bromine Br
35
brown liquid
59
The Halogens
Element Symbol Atomic no. State at room temperature Boiling point OC
Fluorine
Fl
9 17
Chlorine Cl
pale yellow gas green gas
- 188 - 35
Bromine Br
Iodine I
35
53
brown liquid
59
Iodine
A dark purple solid. A strange substance which turns from a solid to a gas when heated – without first turning into a liquid. Used in antiseptic to kill bacteria.
The Halogens
Element Symbol Atomic no. State at room temperature Boiling point OC
Fluorine
Fl
9 17
Chlorine Cl
pale yellow gas green gas
- 188 - 35
Bromine Br
Iodine I
35
53
brown liquid
purple solid
59
184
The Halogens
Element Symbol Atomic no. State at room temperature Boiling point OC
Fluorine
Fl
9 17
Chlorine Cl
pale yellow gas green gas
- 188 - 35
Bromine Br
Iodine Astatine I At
35
53
brown liquid
purple solid
59
184
Astatine
A black solid. Very dangerous and usually radioactive. There is less than 30g in the entire Earth at any one time! Has no use what-soever!
The Halogens
Element Symbol Atomic no. State at room temperature Boiling point OC
Fluorine
Fl
9 17
Chlorine Cl
pale yellow gas green gas
- 188 - 35
Bromine Br
Iodine Astatine I At
35
53 85
brown liquid
purple solid Black solid
59
184 337
(estimated)
The Halogens
Fluorine Chlorine Bromine Iodine
most reactive
least reactive
The Halogens
Fluorine Chlorine Bromine Iodine
most reactive
least reactive
• all have 7 electrons in their outer shell
• all react to pick up an extra electron so that they have full outer shell and are stable!
200
Boiling160 point OC
120 80
40 0 -40 -80 Br
I
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80
Cl
Atomic number
-120 -160 -200 Fl
200
Boiling160 point OC
120 80
40 0 -40 -80 Br
I
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80
Cl
Atomic number
-120 -160 -200 Fl
Graph showing the boiling point of the halogens
200
Boiling160 point OC
120 80
40 0 -40 -80 Br
I
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80
Cl
Atomic number
-120 -160 -200 Fl