Key Definitions Flashcards
ISOTOPES
Atoms of the same element with different numbers of neutrons and different masses
ATOMIC NUMBER
Number of protons and electrons in an atom
MASS NUMBER
Total number of protons and neutrons in the nucleus of an atom
IONS
Particles of an element with different numbers of electrons and protons that also have a charge
RELATIVE ATOMIC MASS
The average mass of an atom compared to 1/12 of the carbon 12 atom
RELATIVE ISOTOPIC MASS
The mass of an isotope relative to the mass of 1/12 of the carbon 12 atom
MOLE
A mole is the amount of a substance that contains as many particles as there are atoms in 12g of carbon
MOLAR MASS
The mass of 1 mole is equal to the relative molecular mass and is written in g/mol
AVOGADRO’S CONSTANT
The total number of atoms in 1 mole. There are 6.02x10^23
MOLECULAR FORMULA
The actual number of atoms of each element in a compound
EMPIRICAL FORMULA
The simplest whole number ratio of atoms of each element in a compound
RELATIVE MOLECULAR/FORMULA MASS
The total atomic masses of each element added together. Relative molecular is used for simple molecules. Relative formula is used for giant structures like ionic
STOICHIOMETRY
The ratio of an amount in moles in an equation
PERCENTAGE YIELD
The amount of substance that is made compared to the theoretical amount of substance.
LIMITING REAGENT
If a reactant is not in excess, it will be used up first, therefore it is the limiting reagent, this is normally the one with bigger amount of moles.
ATOM ECONOMY
How well an atom is used up, a perfect atom economy is 100%
STRONG ACID
When dissolved in water it releases all of its H+ protons and fully dissociates
WEAK ACID
Only releases a small amount of H+ ions when dissolved in water and partially dissociates.
BASE
Metal oxide, metal hydroxide or ammonia
Proton acceptor
ALKALI
Base that releases OH- ions when dissolved in water