1. Non-Metals

2. Announcements
The quiz has been delayed due to the ERB tests and we will have in next Tuesday.
The next quiz on metals will be shortly after (with in a few days)
Poster deadline is 22nd April
Previous question: How would you expect the reactivity to be for sodium vs. caesium?

3. Goal of the class
To introduce and discuss the different types of nonmetals
Question of the day: How are the different types of non metals categorized?
Previous Answer: stability can be predicted based on the size of the atoms.
Previous question: How could the stability of an atom be predicted?

4. Non-Metals
The elements of the periodic table marked in red are non-metals.
Same as before

5. Non-Metals Nonmetals can be broken into different categories
Polyatomic
Diatomic
Monatomic
Can be very reactive or completely unreactive
Solid, liquid or gas
Poly means many
Dia = 2
Mono = 1

6. Noble Gases
Group 8 (0) of the periodic table are called the noble gases.
They were once called the inert gases but that name was changed.
Monatomic nonmetal
Highly unreactive
Full outer shell of electrons
Same as before

7. Properties of Noble Gases
Odourless
Colourless
Very low melting and boiling temperatures
All gases at room temperature
High ionization energy
Same as before

8. Properties of Noble Gases
Reminder from our section on electron orbits, the magic numbers are 2, 8, 8.
helium 2
neon
2,8
Same as before
argon
2,8,8

9. Noble Gases
Helium is less dense than air, so it’s great for all kinds of balloons.
Helium balloons lift instruments into the upper atmosphere to measure atmospheric conditions.
they are good conductors of heat and electricity
they can be hammered or bent into shape easily

10. Noble Gases Hydrogen is less dense than helium and used to be used.
However, hydrogen is highly flammable and is not used anymore.
they are good conductors of heat and electricity
they can be hammered or bent into shape easily

11. Noble Gases
Each noble gas produces a unique color.
Helium glows yellow, neon glows red-orange, and argon produces a bluish-violet color.
The “neon” lights you see in advertising signs can contain any of the noble gases, not just neon.
Electricity is passed through the glass tubes that make up the sign.

12. Noble Gases
Argon is the most abundant noble gas found on earth and makes up about 1% of the atmosphere.
HeNe laser
Many noble gases are used in high powered lasers

13. Halogens
The elements in group 7 of the periodic table, on the right, are called the halogens. I Br Cl F At
fluorine
chlorine
they are good conductors of heat and electricity
they can be hammered or bent into shape easily
bromine
iodine
astatine

14. Halogens Halogens are very reactive non metals.
They are all toxic or harmful because they are so reactive.
Before antiseptics, iodine was used to clean wounds as it is harmful to all things, including bacteria.
Chlorine, bromine, Iodine

15. Halogens
They are also never found free in nature because of their reactivity – they are found as compounds with metals.
These halogen-metal compounds are salts, which give halogens their name – ‘halo-gen’ means ‘salt-former’.
Talk about ions formed Na+, Li+, K+ etc

16. Halogens
All halogens have seven electrons in their outer shell. This means that:
They can easily obtain a full outer shell by gaining one electron.
They all gain an electron in reactions to form negative ions with a -1 charge.
They have similar chemical properties.
fluorine
2,7
chlorine
2,8,7
Talk about ions formed Na+, Li+, K+ etc
bromine
2,8,8,7

17. Uses Fluorine is added to toothpaste to prevent tooth decay
Chlorine is added to the water in swimming pools as a disinfectant or some bleaches.
Conductivity is both thermal and electrical

18. Homework Revise for quiz!