topic 1 atomic structure Flashcards
Substance a contains only one type of atoms and does not conduct electricity
Non-metallic element
Give meaning meaning meaning of isotopes answer in terms of subatomic particles
atoms with the same number of protons but with different numbers of neutrons
which scientist first suggested that electrons orbit the nucleus at specific distances?
bohr
describe three differences between nuclear model of atom and plum pudding model
nuclear-empty space, positive charge in the nucleus, mass is concentrated in nucleus, the electrons and the nucleus are separated
describe the change bohr made to the nuclear model
Electrons orbit the nucleus
Electrons are at specific distances from the nucleus
which gas is produced when group one elements react with water?
Hydrogen
explain why reactivity of elements change going down group one
because the outer electron is further from the nucleus
So there is less attraction between the nucleus and the outer electrons so the atom loses an electron more easily
two statements of the properties of most transition metals
The form ions with different charges, they have high melting points
explain why oxygen is described being reduced in the reaction between sodium and oxygen
oxygen gains electrons
Explain my ammonia has a low melting point
has small molecules
Has weak inter molecular forces
Little energy needed to overcome the intermolecular forces
Describe and explain fractional distillation
A technique for separating mixtures of liquids.
It works when liquids have a different boiling point
What is an atom?
The smallest part of an element that can exist
What is an element?
An element is a substance of only one type of atom
describe and explain simple distillation
simple distillation is used to separate liquid from a solution – the liquid boils off and condenses in the condenser. The firm monitor will read the boiling point of a pure liquid. Contrary to evaporation, we get to keep the liquid. 
Describe and explain crystallisation
.
Crystallisation is similar, but we only remove some of the solvent by evaporation to form a saturated solution. Then we call down the solution. As we do it, the solid starts to crystallise, as it becomes less soluble at lower temperatures. The crystals can be collected and separated from the solvent via filtration.
Describe and explain fractional distillation
fractional distillation is a technique for separation of mixture of liquids. It works one liquids have different boiling poles. The apparatus is similar to one of the simple distillation operators, with additional fractionating colonplace on the top of the heated flask.
The fraction in column contains glass speeds.
It helps to separate the compounds.
In industry, mixtures are repeatedly condensed and vaporise. The column is hot at the bottom and colder the top. Liquids will condense at different heights of the column.
describe and explain filtration
Filtration is used to separate and insoluble solid is suspended in a liquid. The insatiable solid gets caught in the filter paper, because the particles are too big to fit through the holes in the paper. The filtrate is the substance that comes through the filter paper.
Describe and explain chromatography
chromatography used to separate a mixture of substances dissolved in a solvent. In paper chromatography replace a piece of paper with a spark containing mixture in a beaker with some solvent. The bottom of the paper has been contact with the solvent. The solvent level will slowly start rise, this separating thespot into few spots
what is a separating funnel?
A separating funnel is an apparatus for separating immiscible liquids .Two immiscible liquids of different densities or form two distinct layers in the separatory funnel we can run off the bottom layer to separate vessel 
State the colours are flames observed when lithium, sodium and potassium burning in oxygen
crimson-red Lithium
yellow-orange Na sodium
lilac K potassium
describe the properties of noble gases. Discuss the trends in properties down the group.
Non-metal, gases, low boiling points, unreactive
boiling point increases down the group as the atoms get heavier 
What is evaporation
evaporation is a technique for separation of a solid dissolved in a solvent from a solvent. The solution is heated until all the solvent evaporates: the solid stays in the vessel
