Year 9 Half Yearly Flashcards
Who made a discovery in 400 bc
400bc-Democritus
What had democritus thoerised?
Everything was made out of atoms
Atoms are indestructible
What had john dalton theorised
That atoms of same elements where alike
Atoms combined into simple whole number ratios
What had Sir.J.Thomson discovered
Created the first model and referring it looking like a plum pudding
Atoms consisted of a positive charged sphere with electrons in it
How did Lord Rutherford contribute to the atom
Atoms consist of mostly empty space
Has a dense nucleus containg positively charged protons
Negatively charged electrons orbiting around the nucleus
Electrons stop after they run out of energy
What did Sir James Chadwick?
Discovered the neutron
Found out that neutron make a part of the nucleus
Neutrons have no charge
How did Niels bohr add to the atom
He discovered that atoms have shells where electrons spin
He also discovered that electrons do not run out of energy
What is the formula for Atomic Mass(A)
Number of protons+ number of neutrons= Atomic Mass (A)
What is the Atomic Number (Z) formula
Number of protons = Atomic number(Z)
What are isotops
Atoms that have the same of protons and electrons but different numbers of neutrons (same element different mass)
What is electron configuration?
Electron configuration is how electrons are soughted into shells.
Number the layers of the first 3 layers of a atom
2
8
8(18)
Who had a discovery in 1808
1808- john dalton
Who had a discovery in 1897
1897-Sir.j.Thomson
Who had a discovery in 1911
1911-lord rutherford
