Enter your text here ... The halogens are a family of elements in group 7 (aka 17) of the periodic table. in this video, you can see how reactive ...

The NMR facility at Princeton University

Proton NMR produces a spectrum with a  number of peaks.  The number of peaks corresponds to the number of different chem...

image to show the tetrahedral shape of the methane molecule

the alkanes are a family of hydrocarbons. hydrocarbons are compounds containing hydrogen and carbon only. methane is the simplest hydrocarbon wit...

Electronegativity values

 Electronegativity values allow us to predict the direction and strength of dipoles which might exist in molecules

Symbols from AQA trilogy syllabus

Symbols used in electrical circuit diagrams:  Enter your text here ... Enter your text here ...

​1.34 understand that ionic compounds have high melting and boiling points because of strong electrostatic forces between oppositely charged ions1.35 ...

looking for patterns

 1.38 Activity. Know your ions.  Students should: 1.38 know the charges of common ions listed You will have noted from the video that metal ...

the formulae of five polyatomic ions and one monatomic ion to be learnt.

 1.39 Activity. Finding formulae  Students should: 1.39 write formulae for compounds formed between the ions listed Watch the video closely ...

Rust forms on iron and steel as a result of a redox reaction between iron and oxygen.

 2.15 - 2.20 Loss and gain Oxidation and reduction reactions are very commonplace. When a element combines with oxygen that element is said to ha...

Intermolecular forces are responsible for holding together the two strands of a DNA molecule

Before tackling this topic make sure you are able to: explain the difference between intermolecular and intramolecular forces. use...

water expands when it freezes and ice therefore floats

1. Why is water a liquid and not a gas ( between 0 and 100oC) ? Water has a Relative Molecular mass ( Mr) of 18 ... Oxygen's Mr is 32. ...

An Exothermic reaction. Acetylene (Ethyne) releases a lot of energy when it burns.

Enter your text here ... Introduction ​Every chemical reaction has an accompanying change in energy. Some reactions release energy to the surroundings...

The mass spectrum of boron

 1.17 Activity 2. Calculating relative atomic mass.  Students should: 1.17 be able to calculate the relative atomic mass of an element (Ar) ...

 1.16 Activity 1. Three types of carbon atom  Students should: 1.16 know what is meant by the terms atomic number, mass number, isotopes and...

masses and charges of subatomic particles

 1.15 Sub atomic particles  Students should: 1.15 know the structure of an atom in terms of the positions, relative masses and relativecharg...

If a nucleus was the size of a raisin, the rest of the atom would be the size of a sports stadium

 Atomic models Atoms are the building blocks of matter. Atoms are the smallest possible particles into which an element can be subdivided, withou...