Elements and Compounds Can use the diagram to recap last lesson. Labels: Nucleus Protons Neutrons Electrons Shells

Atoms are the fundamental building blocks of the universe. They can be joined together by chemical bonds Analogy here is like lego bricks

From last lesson: Atoms can have different numbers of protons, neutrons and electrons. There are 118 different types of atoms. They can be found on the periodic table of elements.

If something is made of the same type of atom then it is called an element

Complete questions 1-9 on your sheet Extension: find the periodic table of elements in the back of your link book. Start thinking about all the things on it that you notice

The 118 different types of atom all have a name and a special symbol These can be found on the Periodic Table of Elements

When different things are together but not chemically bonded, the result is called a mixture Could use any example, sand in water, pens in a pencil case, students in a room…

Types of Substance

If between 2 and 100 atoms are chemically bonded together, the substance is called a molecule They can be the same atoms or different ones!

Q10-15 in booklet 3. Can have students explain their answers verbally or in their books.

Molecular Substances They are made of individual molecules that are totally separate from each other. This is water which is one of the key examples we will be looking at.

Each substance has a chemical formula. This tells you which atoms the molecules are made of For example, water’s chemical formula is H2O. This means each molecule has two hydrogen atoms and one oxygen atom chemically bonded together. Molecules have between two and a hundred atoms

Fill in the gaps on the worksheet Start reading ahead in the worksheet

Atoms of which elements, and how many of them, are in: H2 O2 H2O CH4 CO2 Q17-25 Do the first one or two together

Giant structures

In one kg of iron there are 1.1x1025 atoms That means in one kg of iron there are: 11000000000000000000000000 atoms

These atoms are all chemically bonded – billions and billions of them on and on and on. This is called a giant structure Mention that this is in three dimensions. Giant doesn’t necessarily mean “big”. 1kg of iron isn’t “big.” But with respect to atoms, it certainly is “big” as we are dealing with many billions of them.

Giant structures can be elements or compounds Iron is an element, iron oxide is a compound. Ratio is incorrect for simplicity. Iron Iron oxide

Complete the next fill in the gaps on the sheet Start reading ahead

We can also write chemical formulae for giant structures E.g. aluminium oxide is Al2O3 It has two aluminium atoms and three oxygen atoms Q26-33 This is a proportional thing. So if you take a lump of iron oxide, 2 out of every 5 will be iron and 3 out of every 5 will be oxygen.