The Halogens & Noble Gases

1. The Halogens & Noble Gases http://soundenergy.net/gas.htm

2. Today’s Lesson • Introduction to The Halogens & Noble Gases • Start write-up for design task • Homework

3. Noble Gases • These are our Group 0 Elements. Some of their properties include: • Non-metals • Colorless Gas • Monatomic (they are found as single atoms) • Unreactive (They don not normally react with anything) • They have a full outer electron shell

4. Noble Gas Trends • It’s atom size gets larger as you go down the Group. • The density increases as you go down the Group • The boiling point increases as you go down the group!!

5. The Halogens • Halogens are four reactive elements found in Group 7. • They have 7 electrons in their outer shell so are very reactive. They are non-metals. • The smaller the Period number, the more reactive they are. • They work in the opposite direction of the Alkali Metals (Group 1) which are more reactive the larger the Period number.

6. Halogens Continued • Halogens have 7 electrons in their outer shell. Atoms are stable when they have full electron shells, so halogens are reactive as they try and get that one last electron. • Halogens can also displace one another. For example, Bromine will displace Iodine, while Chlorine will displace Bromine. http://www.youtube.com/watch?v=F4IC_B9i4Sg

7. Questions • Read The Non-Metal groups in the periodic table on Page 96-97 and answer Q 1-6 in your book.

8. Our Design Task • This design task is a little bit different. You work in groups of around 4 students completing an experiment that you choose. • Please be realistic with the experiment you choose – don’t make it too easy but don’t make it too complex. • The main thing is being able to test a hypothesis and collect data to see if the hypothesis was correct or not.

9. Our Topics • You can complete an experiment on filtration, distillation, separation and crystallization. • I strongly discourage completing distillation – not because of danger but because it’s difficult and is quite boring.

10. Atoms, Elements and Compounds • An atom is a single particle that contains protons, electrons and/or neutrons. • Most of the space in an atom is empty. • An element states the type of atom there is. Gold is a metal that is found in elemental form. When a liquid, gas or liquid only contains one type of atom, it’s called an element.

11. Compounds • When two or more atoms are bonded together, it’s called a compound. • These compounds are chemically held together. There are 3 types of bonding – ionic, covalent and metallic bonding. We will learn about these later. • Read Page 10-11 and answer Q 1-8.

12. Homework