Chemistry Alevel

Atom economy

Measure of the amount of starting materials that become the useful product

The mole

The amount of substance in grams that has the same number of partials as they are in 12 grand of carbon-12

Relative atomic mass

The average mass of an atom compared to one twelfth of the mass of an atom of carbon-12

Relative molecular mass

The average mass of a molecule compared to one twelfth of the mass of an atom of carbon-12

Relative formula mass

The average mass of a formula compared to one twelfth of the mass of an atom of carbon-12

Relative isotopic mass

The average mass of an isotope compared to one twelfth of an atom of carbon-12

Empirical formula

The simplest whole number ratio of atoms of an element in a compound

Molecular formula

The actual number of atoms of an element in a compound

Anhydrous

Without water

Theoretical yeild

The mass of substance that should be formed in a chemical reaction

Cations

Positive ions

Anions

Negative ions

Spectator ions

Ions that play no part in a chemical reaction

Nucleons

Collective name for protons and neutrons

Orbitals

Regions of space outside of the nucleus that electrons occupy

Atomic mass unit

One twelfth of the mass of an atom of carbon-12

Isotope

Atoms of the same element with the same number of protons and a different number of neutrons

Ions

Charged particles that form when an atom loses or gains one or more electrons

Hydrocarbon

Compounds consisting of hydrogen and carbon only

Fraction

A mixture of hydrocarbons of similar chain length and boiling point range

Saturated

Compounds consisting of single carbon-to-carbon bonds

Unsaturated

Compounds consisting double carbon-to-carbon bonds

Functional group

An atom or groups of atoms that when present in different molecules causes them to have similar characteristics

Homologous series

Families of organic compounds that have the same functional group and general formula

Displayed formula

Shows all covalent bonds and atoms in the molecule

Structural formula

Shows enough information to make the structure clear but omits most of the covalent bonds

Skeletal formula

Removes all carbons and hydrogens, each point represents carbons with their corresponding hydrogens

General formula

And algebraic representation of a homologous series

Nomenclature

Naming and drawing from name of organic molecules

Aufbau/building principle

Electrons fill lowest energy orbital first

Hunds rule

Electrons never pair up in orbitals until all orbitals of the same energy level are singly filled. Unpaired electrons have parallel spin

Pauli exclusion principal

Only 2 electrons can occupy the same orbital and they must have a parallel spin

First ionisation energy

The energy required when one mole of gaseous atoms forms one mole of gaseous ions with a single positive charge by losing one electron

Second ionisation energy

The energy required when one mole of gaseous ions with a single positive charge forms one mole of gaseous ions with a double positive charge by losing one electron