1.1 Atoms, Elements, Nuclear Model, Structure, Electrons Flashcards
(23 cards)
Define atom
The smallest part of an element that can exist e.g. O, Na, Cl
Define element
A substance made of only one type of atom e.g. Fe, O2, C.
Define compound
A substance made of two or more different atoms chemically bonded together in fixed proportions e.g. H2O, CO2, CH4.
Define molecule
A substance made of more than one atom chemically bonded together e.g. O2, Cl, H2O.
Define mixture.
Two or more elements or compounds not chemically combined together. The chemical properties of each substance in the mixture are unchanged.
State the type of mixture separated by filtration.
An insoluble solid in a liquid.
State the type of mixture separated by crystallisation.
A soluble solid from a solution.
State the type of mixture separated by simple distillation.
A solution containing two liquids or a solvent from a solid.
State the type of mixture separated by fractional distillation.
A mixture of more than two different solvents.
State the type of mixture separated by chromatography.
A mixture of solvents or solutions.
How was the atom described prior to the development of the atom?
As a tiny sphere that could not be divided.
What led to the development of the Plum Pudding Model?
The discovery of the electron.
What is the plum pudding model of the atom?
A ball of positive charge with negative electrons embedded into it.
What experiment led to the development of the Nuclear Model?
The alpha scattering experiment.
What were the two conclusions from the alpha scattering experiment?
The mass of an atom was concentrated at the centre (nucleus) and the nucleus was positively charged.
How did Neils Bohr adapt the nuclear model?
By suggesting that electrons orbit the nucleus at specific distances.
What evidence supported Neils Bohr’s adapted nuclear model?
The theoretical calculations of Bohr agreed with experimental observations.
How were protons discovered in the nucleus?
Later experiments led to the idea that the positive charge of any nucleus could be subdivided into a whole number of smaller particles, each particle having the same amount of positive charge.
What was James Chadwick’s contribution to the atomic model?
He provided the evidence to show the existence of neutrons within the nucleus.
State the three subatomic particles
Protons, neutrons, electrons.
State the relative charges of the subatomic particles
Protons: +1, neutrons: 0, electrons: -1.
What is the atomic number of an atom?
The number of protons in an atom.
What do all atoms of an element have in common?
The same atomic number (number of protons).
