GCSE Chem: bonding, structure and properties of matter.

What are bonds?

attractions between particles.

What are the 2 types of bonds?

Ionic and covalent

What is structure?

The way in which the particles are arranged.

Why do atoms form chemical bonds?

To try to gain a full outer shell.

What types of bonds occurs between a metal and non metal?

An ionic bond.

Why do metals and non metals form ionic bonds?

Because metals need to lose electrons to gain a full outer shell and non metals need to gain electrons to gain a full outer shell. This means the metal will become positive ( loses and electron ) and non metal becomes negative ( gains an electron ) so they are oppositely charged ions attracted to each other.

Define an ionic bond below:

the electrostatic attraction between oppositely charged ions.

when drawing the dot and cross diagrams for ionic bonds would they be joined or seperate?

seperate

What should the dot and cross diagram of an ionic compound look like?

2 circles showing the electrons with brackets around each one and a plus of minus at the side. One circle should have dots and one crosses and show the moment of the cross.

Name 3 properties of ionic compounds?

they are soluble in water ( mostly ), they have a high melting point and they do conduct electricity ( when solid, do when dissolved or molten ).

What are the structures of ionic compounds?

Giant ionic lattice.

Describe the structure of a giant ionic lattice?

Each ion is ionically bonded to multiple others that are charged oppositely. For example a positively charged metal is ionically bonded to many other negatively charged non metals.

Why do ionic compounds have very high melting and boiling points?

Because the negative and positive ions have very strong forces of electrostatic attraction between them that are very hard to break and move and therefore very hard to melt/boil.

Why do ionic compounds conduct electricity when melted or dissolved but not when solid?

Because electric current is the flow of charged particles and when particles in an ionic compound are solid they are not free enough to move and “flow” and therefore conduct electricity. However when they are in a molten or dissolved the ions are much freer and are able to transmit an electric current.

Why are ionic compounds soluble in water?

Because water molecules are polar which means they have positive and negative ends, this means they pull apart the giant ionic lattice structure causes it to dissolve.

What type of bonds occur between 2 non metal atoms?

covalent bonds.

Why do 2 non metals form a covalent bond?

Because they both need to gain electrons to gain a full outer shell so they share them.

In a dot and cross diagram for a covalent bond are the diagrams crossed or seperate ?

crossed

What should a covalent dot and cross diagram look like?

Joined diagrams sharing electrons.

Define a covalent bond:

A shared pair of electrons between 2 atoms.

How many covalent bonds can each element make?

as many as electrons needed to gain a shell. For example an element in group 6 needs 2 electrons to gain a full outer shell so it can form 2 covalent bonds.

What should a ball and stick diagram look?

Each element and bond. Each line represents each covalent bond.