chemical bonds

Ionic bonding occurs in…

metal and non metal compounds

Covalent bonding occurs in….

Non metal compounds and elements

Metallic bonding occurs in…

metal alloys or compounds

Explain ionic bonding

Between a non metal and metal as they transfer electrons to become more stable

The metal particles lose an electron, becoming positively charged ions

The non metals gain an electron, becoming negatively charged ions

Draw a dot and cross diagram for ionic bonding

Explain covalent bonding

When atoms share one or more pair of electrons

Small molecules (HCl,H²,NH³) have strong covalent bonds within their molecules

Explain metallic bonding

When positive ions (without electrons) ate bonded with delocalised electrons arranged in a regular pattern, free to move throughout the structure

Are Metallica’s bonded structures conductors

Yes because they’re delocalised electrons can carry charge etc

Giant ionic bonds

Held together by strong electrostatic forces between oppositely charged ions acting in every direction as its 3d

Giant ionic bond example

Sodium chloride

Giant ionic structure diagram 1 (lattice)

Giant ionic structure diagram 2 (lattice)

Polymer’s definition

Large covalently bonded molecules

giant covalent structures (macromolecules)

Many atoms covalently bonded in a lattice structure

Giant covalent structures examples

diamond, graphite, silicon, and silicon dioxide

Are metallic bonds strong?

Yes because they have delocalised electrons throughout

Covalently bonded dot and cross diagram

Explain covalent bonds in polymers

Covalent bonds link the repeating units (monomers) in a polymer, forming a long chain molecule. Drawn with a single straight line

Ball and stick diagram

Pros and cons of ball and stick diagrams

Pros

Pros and cons of dot and cross diagrams

Dots and crosses makes it clear where electrons are coming from

Don’t show the shape of the molecule though

Pros and cons of 2d stick diagram (covalent)

Can’t tell which electrons came from where, give no idea of outer electrons not in bonds, don’t give accurate information on shape of molecule

Pros and cons of 3d stick diagrams

Shows the shape

Pros and cons of ball and stick diagrams (ionic 2)

Can clearly see ions in 3 dimensions

Shown as widely spaced when actually they’re packed together, only shows small part of the structure

Space filling diagrams (ionic 1)

Shows how closely packed

Can struggle to see 3d packing, only shows a small part of giant crystal lattice

Empirical formula definition

Simplest ratio of atoms (ions) in a structure

E.g. C²H^6 → CH³

How to find empirical formula

Count the amount of ions of each substance and wrote it down, the simplify

E.g.Na³Cl³ → NaCl

Covalent bond diagram 1

Example polymer structure

Molecular formula

Just count the amount of ions

E.g. H^5Cl^5