Chemistry <3 Flashcards
What did Bohr do?
He realised that occupy fixed energy levels around the nucleus.
Describe Dalton’s atomic theory.
He described atoms as tiny particles which make up matter, which cannot be split.
How can you calculate the number of neutrons in an atom?
Mass number - atomic number
Describe the arrangement and movement of particles in a solid.
Particles are close together in a regular arrangement and vibrate about a fixed position.
What do we call the change of state that occurs when a liquid changes to a gas?
Evaporation / Boiling
What is a physical change?
A change that does not produce a new substance, the substance may change change state or break into pieces.
What subatomic particles are located in the nucleus of an atom?
Protons and Neutrons.
What are the limitations of the particle model?
Does not take into account, size of the particles and the space between the particles.
State the relative masses of the subatomic particles.
Protons : 1 , Neutrons : 1 , Electrons : 0.0005
What is the mass number of a atom?
The number of protons + The number of neutrons in a atom
Describe Rutherford’s atomic theory.
He suggested that the atom has a positively charged nucleus with electrons orbiting around.
Describe Thomson’s atomic theory.
In his plum-pudding model, he described atoms as spheres of positive charge with electrons dotted around inside.
What do we call the change of state that occurs when a solid changes to a liquid?
Melting.
What do we call the change of state that occurs when a gas changes to a liquid?
Condensation.
What do we call an atom that has gained or lost electrons?
Ion.
