1.1 A simple model of the atom, symbols, relative atomic mass, electronic charge and isotopes Flashcards
Roughly how many different elements are there?
100
Atoms have a radius of…
0.1 nanometres
What did ancient greeks think about atoms?
They were tiny particles that cannot be divided
Who discovered ‘solid spheres’ and what was the theory?
John Dalton
different types of spheres make up different elements
Who made the Plum Pudding model and what did it show?
JJ Thompson
The atom is a ball of +ve with -ve electrons embedded in it
What was the Alpha Particle Scattering experiment? by who?
Ernest Rutherford
He fired +ve alpha particles at a thin sheet of gold foil. Some reflected, some deflected and some passed through.
Following the AP experiment, which model of the atom replaced JJ Thompson’s?
Nuclear model by Ernest Rutherford
Who discovered Energy levels? What did they suggest?
Niels Bohr
suggested electrons orbit the nucleus at specific distances in shells
orbiting it prevents the atom collapsing
Who discovered Protons? What did they suggest?
Ernest Rutherford
Said the nucleus has discrete +ve particles
Same charge as a hydrogen nucleus
Most of the alpha particles passed through meaning?
Most of the atom is empty space
Some positive alpha particles were deflected meaning?
The atom has a + charged nucleus
Some alpha particles bounced straight back meaning?
The mass of the atom is concentrated in the centre
What’s an isotope?
A version of an element with the same number of protons but different number of neutrons.
(Different Mass Number)
Relative atomic mass takes into account what?
The abundance of the isotopes of that element
What is an ion?
An atom that has lost or gained electrons therefore has a positive/negative charge
