Unit 1 :0 :) Flashcards
What was the name of Thomson’s model?
Plum Pudding Model
What did Millikan do?
He performed the Oil Drip experiment and this discovered the charge of one electron and then determined their locations in the atom
What is an alpha particle?
A positively charged particle
What did Dalton do?
He wrote the paper on atomic theory
Who used a cathode ray tube to prove the beam was composed of negatively charged particles?
Thomson
What was Democritus’s profession?
He was a Greek philosopher
What did Democritus discover?
The atom (which he believed was inseparable)
What did Democritus say about the elements?
There were only four of them (fire, water, air, earth)
What did Democritus’s model of the atom look like?
It was just a circle )
Who discovered the atom?
Democritus
What did the scientist who performed the Golf Foil experiment think was supposed to happen to the atom? What actually happened?
he thought the atom was just going to pass through the foil, but instead some parts of it also bounced off
What did Thomson’s atom model look like?
It was a circle with electrons evenly spaced out in it (and the space that wasn’t an electron and filled up the rest of the circle was positive)
What did Thomson do?
He discovered that there was an negatively charged particle and named it an electron
What is the difference between Rutherford and Thomson?
Thomson discovered the electron and that it was negatively charged (cathode ray tube experiment), while Rutherford discovered the nucleus of an atom through his Gold Foil experiment
What was the name of Thomson’s experiment?
The Cathode Ray Tube experiment
What was the name of Rutherford’s experiment?
Gold Foil experiment
What was the Chadwick’s experiment?
Bombarding Beryllium with alpha particles
What was the name of Millikan’s experiment?
Oil Drip experiment
What people didn’t change the model of the atom?
Dalton and Rutherford
What 5 points did the atomic theory boil down to?
- There are more than 4 elements. All of them are made of atoms
- Atoms of the same element have the same mass and properties
- Chemical reactions have to follow the conservation of mass
- Atoms combine in simple whole # ratios to form compounds (Law of Multiple Proportions)
- Compounds contain fixed and constant proportions of its component elements (Law of Definite Proportions)
What did Dalton’s atom model look like?
It was just a circle
Who wrote the paper on the atomic theory?
Dalton
What did Chadwick do?
He discovered the nuetrons
Was Democritus an actual scientist?
No.
What did Rutherford do?
Discovered that there’s a nucleus at the center of the atom with his Gold Foil experiment
Who completed the Gold Foil experiment and discovered the nucleus of an atom?
Rutherford
What is an extensive property?
A property that depends on the amount of matter in the sample
What is an intensive property?
A physical property that doesn’t change no matter how much substance there is
What is a pure substance?
A substance made up of 1 single substance (element/compound)
What is a mixture?
A combination of 2 or more pure substances; can be homogeneous or heterogeneous
What is it called when a substance changes into 1 or more new substances?
It undergoes a chemical change
What is an isotope?
It’s when atoms are chemically identical yet have different atomic weights.
What is the atomic number?
The number of protons
What is the atomic mass?
Protons + neutrons
What are isotopes caused by?
It’s caused by a varying number of neutrons
How can the parts of an atom vary?
Protons = type of element changes
Neutrons = mass changes and isotope is created
Electrons = atom becomes ion
What happens if a neutral atom looses electrons?
It gets a positive charge (cation)
What happens if a neutral atom gains electrons?
It gets a negative charge (anion)
