1.3 Flashcards
What did the Aristotle believe matter was made of?
Didn’t believe All particles are made of tiny pieces of matter called atoms.
He believed all matter is made up of combinations of earth air fire water
What did the Greek philosophers believe matter was made of?
Atomos. The smallest piece of matter
Who were the alchemists?
Researchers in Middle Ages who tried to turn common metals into gold
Who was John dalton? (1766-1844)
- credited with developing new way of explaining matter
- studied gases that make up atmosphere
- matter is made of small hard spheres
- different for every element
- smallest element particle=atom✌️✌️
Dalton’s atomic theory (all false)
- All matter is made of small particles called atoms
- It’s cannot be created or destroyed or divided into small pieces
- All Atoms of the same element are identical mass and size but different from different elements
- Compounds are created when atoms of different elements linked together in definite proportion
Who was jj Thompson (1856-1940) created atomic theory #2
- Studied Electric currents in gas discharge tubes
- determined that currents were streams of negatively charged particles=electrons
- atoms are made of smaller particles
- “raisin bun” model of the atom
What was Ernest rutherfords atomic theory #2?
Experimented with charged particle
Particles deflected in different directions
Tiny dense centre of atom where the electrons moved around=nucleus
What was neihls Bohr atomic theory #3?
Studied gaseous samples of atoms
Glowed when passed by electric current
Electrons surround the nucleus in specific energy levels
What does the smallest particle retain?
It retains all properties of the element
What 3 particles are atoms made of
3 subatomic particles:
Protons +
Electrons -
Neutrons =
