DEFINITIONS SO FAR Flashcards
Atomic number
The number of protons in the nucleus of the atom
Mass (nucleon) number
The number of particles (protons and neutrons) in the nucleus
Isotopes
Atoms of the same element with the same number of neutrons but a different number of neutrons
Ions
An electrically charged particle formed by the loss or gain of one or more electrons from an atom or group of atoms
Relative isotopic mass
The mass of an atom of an isotope compared to 1/12th the mass of carbon 12
Relative atomic mass Ar
The weighted mean mass of an atom of an element compared to 1/12th the mass of carbon 12
Relative molecular mass Mr
The weighted mean mass of a molecule compared with 1/12th of the mass of an atom of carbon 12 (ONLY applies to simple covalent molecules e.g. O2 or CO2)
Relative formula mass
The weighted mean mass of a formula unit compared to 1/12th of the mass of an atom of carbon 12 (Can apply to ionic substances as they occur as giant lattices)
Molar gas volume
Volume per mole of gas.
Units= dm^3 mol^-1
At RTP= 24.0dm^3 mol^-1 approx.
Concentration (of a solution)
The amount of solute, in mol, dissolved per 1dm^3 (1000cm^3) of solution
Dilution
The process of decreasing the concentration of a solute in solution. Adding more solvent without adding more solute will reduce the concentration.
Compound
Atoms chemically joined
Molecule
2 or more atoms bonded with covalent bonds
Bond enthalpy
Average energy required to break one mole of that type of bond
Covalent bond
A shared pair of electrons
Ionic bond
Attraction (electrostatic) between oppositely charged ions
Element
Substance which contains only 1 type of atom
Orbital
A region that can be occupied by up to 2 electrons with opposite spins
Dative bond
Both of the shared electrons originate from the same species
Electronegativity
The ability of an atom to attract the bonding electrons in a covalent bond
Accuracy
How close to the true value a measurement is
Activation energy
Minimum energy required to start a reaction by breaking bonds in the reactants
Aim
The purpose of the investigation
Amount of substance
The quantity whose unit is mole. Amount of substance=counting atoms