Atomic structure of the first elements What things are made of

Atoms, elements and compounds Learning objectives: to learn how we represent atoms and elements Learning outcomes I can classify elements into solids, liquids and gases when given information (F) I can define an element, (D)   I can recognise names, symbols, formulae and diagrams of elements or compounds (C) Starter: 5-4-3-2-1 List 5 solids, 4 metals, 3 non-metals, 2 gaseous elements at room temperature, and 1 liquid element at room temperature.

Elements What is an element? Elements are made from one type of atom. Its a pure substance Hydrogen sodium

Sodium chloride (salt) Compounds What is a compound? A compound is two or more elements chemically bonded together. It is a pure substance. Hydrochloric acid Sodium chloride (salt)

Mixtures What is a mixture? A mixture is Two or more elements or compounds mixed together but not chemically bonded. Impure substances. Salty water Air

Elements and compounds Reactants (for each say element or compound) Products iron sulfur magnesium oxygen hydrochloric acid

HCl ZnSO4 NaCl O2 CuO H2O Mg MgCl2 CuSO4 ZnO NaOH Zn

HCl ZnSO4 NaCl O2 CuO H2O Mg MgCl2 CuSO4 ZnO NaOH Zn Element or compound? HCl ZnSO4 NaCl O2 CuO H2O Mg MgCl2 CuSO4 ZnO NaOH Zn

Close up atoms

Closer still… 24 12 Mg electron - 12 proton + neutron

How many protons, electrons and neutrons does fluorine have? 19 9 F Atomic weight Number of protons AND neutrons Atomic number Number of protons (Number of electrons too) electron - Proton + Neutron 9 9 10

How does this look? 19 9 F electron - 9 Proton + Neutron 10

Are all atoms the same weight? 1 H An element will ALWAYS have the same number of protons 2 1 H But … sometimes they have different numbers of neutrons 3 1 H These are called ISOTOPES

These are called ISOTOPES 12 6 C Carbon will ALWAYS have the same number of protons 13 6 C But … sometimes it will have different numbers of neutrons 14 6 C These are called ISOTOPES

Only electrons go in shells How do the shells work? Shells Only electrons go in shells

We number shells from the middle 1 This will be shell 2 This will be shell 3 This will be shell

F Shell 1 will hold 2 electrons Shell 2 will hold 8 Shell 3 will hold 19 9 F Shell 1 has electrons Shell 2 has Shell 3 has 2 7 This is fluorine. It has electrons. 9 * Once you get past element 20 things get a little more complicated!

P Shell 1 will hold 2 electrons Shell 2 will hold 8 Shell 3 will hold Shell 1 has electrons Shell 2 has Shell 3 has 2 31 15 P 8 5 This is phosphorus. It has electrons. 15 * Once you get past element 20 things get a little more complicated!

Ca Shell 1 will hold 2 electrons Shell 2 will hold 8 Shell 3 will hold Shell 1 has electrons Shell 2 has Shell 3 has Shell 4 has 2 40 20 Ca 8 8 2 This is calcium. It has electrons. 20 * Once you get past element 20 things get a little more complicated!