Atomic Theory Flashcards
What was Leucippus and Democritus idea?
If you cut something in half enough times, eventually you’ll reach a particle that can’t be cut anymore.
What is the Law of Conservation of Mass about?
It states that even if matter changes in shape or form, its mass stays the same
What did James Dalton state about elements?
All matter was composed of atoms, indivisible and indestructible building blocks. Atoms of an element were identical, different elements had atoms of differing size and mass.
What did J.J. Thompson conclude about Eugen Goldstein’s discharge tube?
Cathode rays were in fact very light and small negatively charged particles, called corpuscles.
What is the plum pudding model?
The positive ball being the cake, and the electrons are the floating bits of frut within it. Visualized atom by J.J. Thompson.
What was Earnest Rutherford’s experiment?
He shot alpha rays to an extremely this sheet of gold and expected the rays to go straight through.
What is the planetary model, and who proposed it?
It is proposed by Neil Bohr, represents the electrons in orbits around a small central nucleus.
What does the Quantum Theory state?
Electrons weren’t particles or waves, instead they had properties of both and neither
What is an orbital?
A certain region where an electron is much more likely to be found.
What is a Quantum Model or the Cloud Model?
Quantum style atoms are often drawn as clouds with the intensity of color representing not individual electrons but the probability of finding an electron in any particular position.
What is the Dalton’s atomic theory?
- all matter is made of atoms, which are indivisible.
- all atoms of a given element are identical in mass and properties.
- compounds are combinations of two or more different types of atoms.
- a chemical reaction is a rearrangement of atoms.
What does the Dalton’s atomic theory base on?
the law of conservation of mass and the law of constant composition.
What does the law of constant composition state?
It states that samples of a pure compound always contain the same elements in the same mass proportion.
