Atomic Structure Flashcards
Who first put forward the idea of matter being composed of Atoms?
Greek philosophers Democritus and Leucippus, 2000 years ago.
Who came up with the four ‘elements’ model?
Earth, water, fire, air
Greek philosopher, Aristotle
When was the idea of atoms taken seriously again, and who suggested it.
1808, when John Dalton published his atomic theory.
When was the electron discovered and who was responsible?
1897, by J.J. Thomson.
What was the first model used to theorise the shape of atoms.
The plum pudding model.
Negative electrons embedded in a positive sphere.
Who discovered the proton, and came up with the current theory on the structure of atoms?
Ernest Rutherford.
He compared the structure of atoms to planets orbiting a star
Who discovered the neutron
James Chadwick
What is the relative mass of protons, neutrons and electrons?
Protons, 1
Neutrons, 1
Electrons 1/1840
How do you find the number of protons in an atom?
Atomic number.
No of protons = no of electrons.
How do you find the number of neutrons in an atom?
Mass number - atomic number
How many electrons can the first shell hold?
How many electrons can the other shells hold?
2
8
What is the electronic configuration of:
23
Na
11
2,8,1
What is an isotope?
Isotopes are atoms in an element with the same atomic number but a different mass number, indicating a different number of neutrons.
How do you calculate the average mass number of an element (Eg chlorine)?
((% of isotope) x (mass no of isotope)) + ((% of isotope 2) x (mass no of isotope 2))
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Total abundance (100)
What are atoms with electric charges called?
Ions
