P1.1 Flashcards
How did the plum-pudding model describe the atom?
A ball of positive charge, with negatively charged electrons distributed evenly throughout it.
Prior to the discovery of the electron what was believed about the atom?
The atom was believed to be indivisible
Which experiment led to the plum-pudding model being discarded?
Rutherford’s alpha-scattering( gold leaf) experiment.
What is the name given to the currently accepted model of the atom?
The Bohr nuclear model
What are the three subatomic constituents of an atom?
proton
neutron
electron
Describe the arrangement of protons, neutrons and electrons in an atom.
The protons and neutrons are found in the atom’s nucleus
The electrons are found in discrete energy levels around the nucleus.
What type of charge does the nucleus of an atom have? Why?
Positive charge, as the nucleus contains protons, which have positive charge and neutrons which have no charge.
Where is most of the mass of an atom concentrated?
In the nucleus
Approximately what proportion of the total radius of an atom is the radius of the nucleus?
1/10,000
This equals 0.01%. The nucleus is very small compared to the whole atom.
Give an approximation for the radius of an atom.
1x10^-10 metres
What is the definition of density? State the relevant equation with units.
The mass per unit volume of a material
d=m/v
Density(kg/m^3), Mass(kg) and volume(m^3)
Describe the particle arrangement of a solid
Tightly packed in a regular arrangement. Particles can only vibrate on the spot.
Describe the particle arrangement of a liquid.
Close together, but irregular arrangement. They can flow past each other.
Describe the particle arrangement of a gas
Separated, with no regular arrangement. Particles can move freely.
Give the different states of matter in order( least to most) of density of atoms.
Gas
Liquid
Solid
