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Links for Chapter 12: The Periodic Table

On-line Periodic Tables

WebElements

Masses of useful information about the elements and their simple compounds. The only downside is that it is plagued with obtrusive advertisements. Either use ad-block software or try one of the other Periodic Tables below if this offends you.

Fast Periodic Table

From www.schoolscience.co.uk (produced by the UK Association for Science Education). Interactive Periodic Table with lots of information available, from melting and boiling points to discovery and uses.

Discovery dates

A simple interactive Periodic Table which enables you to track the discovery dates of the elements and relate them to things like reactivity and percentage abundance in the Earth's crust.

Periodic Table videos

From the University of Nottingham. Enjoyable, often quirky, video clips about every single element. Likely to be several minutes long for each element. Use this to find out about elements like francium or astatine at the bottom of the Groups you are studying.

The Tom Lehrer elements song

Not actually a Periodic Table, but Tom Lehrer's famous song does list all the elements. Everybody doing Chemistry should have listened to it, and this particular version couples it with a very simple, but neat Flash animation.

Video clips and animations

Trend in densities of the Noble Gases

Neat demonstration from the Open University. YouTube

Reactions of Group 1 metals with water

Again from the Open University. There are some dodgy versions of these reactions on the web, but you can take this one to be accurate and reliable. Students sometimes wonder what is thrown into the trough at the end of the rubidium reaction. I think it is the glass phial that the rubidium was originally stored in. YouTube

Reactions of Group 2 metals with water

This brief video shows the effect of dropping the metals magnesium, calcium, strontium and barium into water. Although Group 2 isn't on the Edexcel IGCSE syllabus as such, this shows that the same trend to increasing reactivity as you go down the Group happens here as in Group 1. However, the Group 2 metals are less reactive compared with the corresponding ones in Group 1 - for example, magnesium is a lot less reactive than sodium; calcium is a lot less reactive than potassium, and so on. You will, of course, be expected to know the reactions between both magnesium and calcium and water. From Mike Thompson's ChemPics on YouTube.

The reaction between sodium and chlorine

Burning sodium in a gas jar of chlorine. The commentary uses the word "exothermic". That means that heat is produced during the reaction. YouTube

The reaction between hydrogen and chlorine

As the notes on the screen to the top right of the video say, this reaction can sometimes by started by the light from the magnesium flame rather than the flame itself. It is also quite scary to mix these gases if you are standing in bright sunlight! From Mike Thompson's ChemPics on YouTube. Be sure to read the information notes.

Physical properties of the halogens

Physical properties of chlorine, bromine and iodine. YouTube

Another look at bromine and iodine

I have included this short clip because it shows that it is perfectly possible to get liquid iodine. The impression is often given that iodine sublimes when you are heating it, going straight from solid to vapour. In fact it is possible to get liquid iodine, although only over a small temperature range. However, when the vapour is cooled, it does go straight from vapour to solid. From Mike Thompson's ChemPics on YouTube. Be sure to read the information notes.

Reactions of the halogens

Physical and chemical properties of the elements from fluorine to iodine in Group 7. From the Open University. The commentary uses the word "valency" a couple of times, and talks about aluminium being "trivalent". These are rather old-fashioned terms and relate to the way the atoms combine with other things. The halogens have 7 electrons in their outer level, one of which is unpaired. They commonly combine with one other atom either via covalent or ionic bonding. Whichever way, the single electron gets paired up. The halogens are said to have a valency of 1, or to be univalent. Similarly, aluminium is referred to as being trivalent, because it has 3 outer electrons which it uses in bonding. YouTube.

Reactions of chlorine with salts of other halogens

This brief video shows the effect of adding chlorine water (a solution of chlorine in water) to solutions of a chloride, a bromide and an iodide. You normally use either the sodium or potassium salts, because these are readily available. You wouldn't expect the chlorine to have any effect on a chloride, but the other two behave exactly as described on page 107 of the book. From Mike Thompson's ChemPics on YouTube.

Reactions of bromine with salts of other halogens

This brief video shows the effect of adding bromine water (a solution of bromine in water) to solutions of a chloride, a bromide and an iodide. This is more difficult to interpret than the previous video, because of the colour of the original bromine water.

Notice that the colour darkens when the bromine water is added to a solution of an iodide. That's because iodine is formed. In the two other cases, the orange solution formed just contains a diluted form of the bromine water - diluted by the water in the chloride and bromide solutions. In other words there is no obvious reaction with these. In fact there is no reaction with these. You will find the chemistry of the reaction between bromine and a solution containing iodide ions on page 108 of the book. From Mike Thompson's ChemPics on YouTube.

Reactions of iodine with salts of other halogens

This very short video completes the series. In this case, there are no reactions at all because iodine is less reactive than the other halogens. For interest, the iodine solution isn't a solution of iodine in water. Iodine is only very, very slightly soluble in water and produces a pale brown solution. The red solution being used is a dilute solution of iodine in potassium iodide solution. From Mike Thompson's ChemPics on YouTube. Be sure to read the information notes.


Instructions for practical work

I have referred to practicalchemistry.org as a reliable source of instructions for experiments. If you find anything really good from other sources, could you let me know via the address on the about this site page of Chemguide.

Periodic Table menu

Contains experimental work on the elements and their compounds.


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© Jim Clark 2009