The Periodic Table / Metals and non-metals

  • The periodic table is split into metals and non-metals

  • In the periodic table each letter represents a different element. These letters are called symbols.

  • An element is a pure substance made from one type of atom. Each element has a unique symbol made from sometimes one or two letters.

  • Chemically similar elements are put together in groups.

A chemical formula represent atoms and elemnts where more than one substance is bonded together.

An element is a substance that can’t be broken down. Each elemnt is made up of its won type of atom. Oxygen, Magnesium, Gold, Iron are all element.

A symbol is a letter that represents an element. Eg:

H = Hydrogen, C = Carbon, He = Helium, Mg = Magnesium

Compounds

A compound is a pure substance which is made from more than one element, and atoms, they chemically bond together to make a compound, and this means we can describe these compounds with a chemical formula.

Examples

  • Water is a compound of hydrogen and oxygen. The symbols H for hydrogen and O for oxygen are used to represent H₂O.

  • Oxygen gas is a molecule made of two oxygen (O) atoms represented as O₂.

  • Sulfuric acid is a combination of hydrogen (H), sulfur (S) and oxygen (O) represented as H₂SO₄.

H₂O

Two hydrogen atoms, one oxygen atom

3 atoms in total

CO₂

One carbon atom, two oxygen atoms

3 atoms in total

Chemical properties

  • In physical changes, no new substances are formed

  • In Chemical reactions, new substances are formed.

During chemical reactions, colour changes may occur, a gas be formed or energy be released.

It is difficult to reverse chemical changes

The chemical properties describe how a substance reacts with other substances

The chemical formula is the ratio of elements in a compound.

Chemical trends

  • Elements in the same group of the periodic table have similar physical properties and chemical properties

Conversion of mass is the formation of a new substance

Reactants are substances that react together to form the products

Product is the substances created in a chemical reaction

Compound is two or more elemnts chemically joined together

Oxidation is where a substance gains oxygen in a reaction

Salt is a a products formed when an acid reacts with a metal or a metal giving substances.

Reactivity series is a chart showing metals in order of decreasing reactivity

Metalloids have properties of both metals and non-metals