definitions Flashcards
define lattice
millions of atoms in a regular structure
regular arrangement of alternating positive and negative ions.
define an Atom
The smallest particle that cannot be further broken down.
define a compound
2 or more diff. types of atoms chemically bonded together
define a molecule
particles made of 2 or more atoms covalently bonded together (can be same or diff. type of atoms)
define an element
same type of atoms
define an ion
a charged particle
define aqueous
dissolved in solution
define molten
melted
(off topic) define Resolution
the smallest reading on a piece of equipment.
eg, stop watch counts 2.05s,, the resolution (smallest reading is 0.05)
define volatile
turns to a gas easily (low boiling point)
define diffusion
moment of particles from a region of high concentration to a region of low concentration as a result of their random motions
define pressure
force acting perpendicular to a surface per unit area
define net force
define net force
define a mixture
2 or more elements / compounds mixed together that can be separated by physical means
Define an isotope
Atoms of the same element with the same number of protons and electrons but a different number of neutrons
define an ionic bond
transfer of electrons between positive metal ions and negative non metal ions
define metallic bond
positive metal ions in a ‘sea’ of delocalised electrons
define malleable
can be bent or hammered into shape
define ductile
can be drawn into wires
define a covalent bond
shared pair of electrons between non metals
define molecular formula
number of each type of atoms present (chemical formula)
define empirical formula
simplest whole number ratio of atoms present
define relative atomic mass
the average mass of isotopes of an element compared to 1/12 of the mass of an atom of carbon 12
define atomic mass
proton + neutron
define atomic number
proton
define relative molecular mass
sum of relative atomic masses in molecular formula
name for group 1
alkaline metals
define relative formula mass
sum of relative atomic mass in empirical formula
name for group 2
alkaline earth metals
name for group 7
halogens
name for group 0
noble gases
define precipitate
solid product
define exothermic reaction
a reaction that releases energy
define endothermic reaction
a reaction that absorbs energy
define physical change
involves a change in substance’s form
define pure
a substance that contains a single element or compound, not mixed with any other substances
define chemical change
involves making a new substance and change in energy
define impure
a substance that contains more than 1 element or compound, mixed with other substances
define solvent
substance that dissolves a solute
define solute
a substance that is dissolves in a solvent
define mixture
contains 2 or more substances not chemically combined
define solution
mixture that is made up of 1 or more substances
define solubility
how easily a substance dissolves
define saturated solution
solution containing maximum concentration of a solute dissolved in a solvent at a given temp.
(no more solute can dissolve in it)
define residue
a substance that remains after distillation, evaporation or filtration
define crystallisation
when a liquids that contains soluble solute is evaporated to leave the soluble solute behind
define filtrate
solution at pass through a filter paper
define evaporation
turning the liquid into gas to be lost from the substance using heat
define immiscible and miscible
-immiscible- liquids that don’t mix
-miscible- liquids that mix
define filtration
passing solution over a filter paper and collecting the filtrate
define chromatography
method of separating mixtures of soluble substances
define stationary phase
the paper in paper chromatography
define a chromatogram
result of separating the components of a mixture by chromatography
define the mobile phase
solvent in paper chromatography
define Rf value
retention factor
define baseline
line that is drawn in an insoluble substance and where the inks are placed
define solvent front
-furthest point the solvent travels
-for calculating Rf value
define successful collision
-collisions with enough energy to react
define anomaly
result that doesn’t fit the pattern
define limiting reactant
reactant that is used up first in a reaction
define activation energy
The minimum energy colliding particles require to react
define catalyst
-substance that speeds up the rate of a reaction but is unchanged at the end of the reaction
define exothermic reaction
-reaction that transfers heat energy to surrounding so temp. goes up
define endothermic reaction
-reaction that absorbs heat energy from the surrounding so temp. goes down
define Enthalpy change
-The difference between the energy required to break bonds and the energy released to make bonds
define delocalised
free to move
define alloy
A mixture of a metal with another substance
define brass
An alloy of copper and zin
define steel
alloy that contains iron and other substances
define ore
A rock that contains a high enough percentage of metal for economic extraction
define galvanizing
coating iron/ steel in a layer of zinc
define hematite
-ore containing iron oxide
-Fe2O3
define bauxite
-ore containing aluminum oxide
-Al2O3
