T1 atomic structure and the periodic table
No description yet. This curated deck is ready for daily study.
Card preview (24)
what is an atom
smallest part of an element what can exist
what is an element
substance of only one type of atom
what 2 groups can elements be classified into
metals and non-metals
what is a compound
two or more elements combined chemically in fixed proportions which can be represented by formulae
do compounds have the same properties as their constituent elements
no, they have different properties
what is a mixture? does it have the same chemical properties as its constituent materials?
mixture consists of two or more elements or compounds not chemically combined together does have the same chemical properties
what are the methods through which mixtures can be separated do these involve chemical reactions
filtration, crystallisation, simple distillation, fractional distillation, chromatography don’t involve chemical reactions
describe and explain simple distillation
used to separate liquid from a solution - the liquid boils off and condenses in the condenser thermometer will read the boiling point of the pure liquid, get to keep the liquid
describe and explain crystallisation
solution is heated and some of the solvent evaporates, leaving behind a saturated solution saturated solution is allowed to cool and crystals to form crystals can be separated by filtration
describe and explain evaporation
technique for separation of a solid dissolved in a solvent from a solvent (eg salt from H2O) solution is heated until all the solvent evaporates, the solids stays in the vessel
describe and explain fractional distillation
technique for separation of a mixture of liquids, works when liquids have different boiling points the fractionating column contains glass beads, helps to separate the compounds industry - mixtures are repeatedly condensed and vapourised column is hottest at bottom and coldest at top liquids will condense at different heights
describe and explain chromatography
place a piece of paper with a spot containing a mixture in a beaker with some solvent bottom of paper has to be in contact with the solvent solvent level will slowly start to rise, separating the spot into few spots
what is a separating funnel
apparatus for separating immiscible liquids two immiscible liquids of different densities will form two distinct layers in the separatory funnel can run off the bottom layer (liquid with greater density) to a separate vessel
describe the plum-pudding model
atom is a ball of positive charge with negative electron embedded in it
describe the Bohr/nuclear model and how it came about
suggests that electrons orbit the nucleus at specific distances (shells) - came about from the alpha scattering experiments
what did the work of James Chadwick provide evidence for
existence of neutrons in the nucleus
relative masses and relative charges of the proton, neutron and electron
Masses: 1, 1, very small charges: 1, 0, -1
radius of an atom
0.1 nm
radius of a nucleus and what is it compared to that of the atom
1x10-14 m and 1/10000
name given to the number of protons in the nucleus
atomic number
atoms of the same element have the same number of which particle
protons
what is the mass number
total number of protons and neutrons
equation for the number of neutrons using mass number and atomic number
subtract atomic number from the mass number
what is an isotope do isotopes of an element have the same chemical properties
atoms of the same element that have a different number of neutrons have the same chemical properties as they have the same electron structure