Atomic Structure Flashcards
Define the word ‘Element’
A pure chemical substance consisting of only one type of atom.
Define ‘Mixture’
A compound made up of two or more different types of atom.
Define ‘Compound’
A molecule containing two or more different types of atom chemically bonded together.
Define ‘Atom’
The smallest part of an element that can exist.
What is the ‘Conservation of Mass’?
The mass of the products after a reaction is equal to that of the reactants.
When magnesium is burnt with oxygen, what is produced?
Magnesium oxide
What does ‘Filtration’ separate?
Soluble solids from insoluble solids.
Give an example of how ‘Filtration’ can be used
Salt (soluble) and sand (insoluble) can be separated by dissolving the salt in water, filtering the sand out, then evaporate the water to leave the salt.
What does ‘Crystallisation’ do?
Obtains soluble solids from a solution.
Give an example of ‘Crystallisation’
Salt crystals can be obtained from water by gently heating and evaporating the water leaving pure salt crystals.
What does ‘Simple distillation’ do?
Obtains a solvent from a solution.
What does ‘Fractional Distillation’ do?
Separates mixtures with different boiling points.
What does ‘Chromatography’ do?
Separates the different soluble, coloured components of a mixture.
In ‘Chromatography’, which phase is the solvent called?
Mobile Phase
In ‘Chromatography’ what phase is the paper called?
Stationary Phase
What did Thomson think the atom contained and what was his model called?
A ball of positive charge surrounded by a sea of electrons. (Plum pudding model)
Which experiment did Geiger and Marsden carry out?
Fired alpha particles at a thin sheet of gold.
What happened to the alpha particles during Geiger and Marsden’s experiment?
Most of the positively charged particles passed straight through the gold sheet, however a tiny number were deflected back.
When Rutherford looked at the results from Geiger and Marsden’s experiment, what did he conclude?
Positive charge in an atom must be concentrated in a very small area- the nucleus. (Nuclear Model came from this)
What did Bohr deduct?
Electrons must orbit the nucleus at specific distances.
Why did Bohr think electrons must orbit the nucleus at specific distances?
They would spiral inwards.
What did Chadwick provide evidence for?
Neutrons within the nucleus.
What did later experiments suggest?
Protons in the nucleus created the positive charge.
What is an ‘Isotope’?
An element with the same number of protons and electrons, but a different number of neutrons.
Metal atoms ….. electrons to form ………. ions.
lose ….. positive
Non-metal atoms ….. electrons to form ………. ions.
gain ….. negative
What do the electrons in an atom occupy?
The lowest available shell / energy level.
For the first 20 elements, how many electrons can the first shell hold?
2
For the first 20 elements, how many electrons can the second and third shells hold?
8
What does the electron configuration of an atom show?
How the electrons are arranged in shells around the nucleus.
Define ‘Electron’
A negatively charged subatomic particle.
Define ‘Neutron’
A neutrally charged subatomic particle.
Define ‘Proton’
A positively charged subatomic particle.
What is the relative atomic mass of a proton and a neutron?
1
What happens when ‘Lithium’ is added to water?
Fizzes steadily, until it disappears.
Define ‘Atomic number’
The number of protons in an atom.
