Chemistry Chemical Changes And Structures

Front 1

Average rate of reaction calculated from graph

Back 1

Calcualtions of the average rate of a chemical reaction from a graph of the change in mass and volume against time.

Front 2

Nuclide notation

Back 2

Chemists use nuclide notation to show the numbers of sub-atomic particles in an atom or ion.

Front 3

Isotopes

Back 3

Isotopes are atoms of the same element with different mass numbers.

Front 4

Relative atomic mass

Back 4

Relative atomic mass is the average mass of the isotopes present taking into account their relative proportions.

Front 5

Ions

Back 5

When there is an imbalance in the number of positive protons and electrons the particle is known as an ion.

Front 6

Ionic bonding

Back 6

Ionic bonds are the electrostatic attraction between positive and negative ions. Ionic compounds from lattice structures of oppositely chraged ions.

Ionic compounds have high melting and boiling points because strong ionic bonds must be broken in order to break down the lattice.

Dissolving also breaks down the lattice structure.

Ionic compounds conduct elecrticity, only when molten or in solution due to the breakdown of the lattice resulting in the ions being free to move.

Front 7

Covalent Bonding, Covalent Molecular, Covalent Network

Back 7

In a covalent bond, the shared pair of electrons is attracted to the nuclei of the two bonded atoms.

More than one bond can be formed between atoms leading to double and triple covalent bonds.

Covalent substances can form either discrete molecular or giant network structures.

Diagrams show how outer electrons are shared to form the covalent bond(s) in a molecule and the shape of simple two-element compounds.

Front 8

Physical properties of chemical explained through bonding

Back 8

Covalent molecular substances have low melting and boiling points due to only weak forces of attraction between molecules being broken.

Giant covalent network structures have very hight melting and boiling points because the network of strong covalent bonds muct be broken.

Experimental procedures are required to confirm the type of bonding present in a substance.