Atomic Theory

Question 1

all matter is made up of small indivisible particles (atomos)

Answer 1

democritus (450 bc)

Question 2

each element is composed of small particles

all atoms of an element are identical but different from those of other elements

atoms cannot be created nor destroyed

a given compound always has the same relative number and kinds of atoms

Answer 2

john dalton’s atomic theory

Question 3

plum-pudding model (electrons embedded in a large positively-charged atom)

discovered electron

Answer 3

jj thomson

Question 4

a high voltage is applied across two electrodes at one end of the tube, which causes a beam of particles to flow from the cathode (the negatively-charged electrode) to the anode (the positively-charged electrode). Eventually led to the discovery of subatomic particles, particularly electrons.

Answer 4

cathode ray tube

Question 5

nuclear model (atoms are neutrally charged; protons are located at the center of the atom)

he discovered nucleus of an atom

Answer 5

ernest rutherford

Question 6

has positive charge; located in nucleus

Answer 6

proton

Question 7

has zero charge; located in nucleus

Answer 7

neutrons

Question 8

has negative charge; orbits the nucleus

Answer 8

electron

Question 9

nuclear model similar to Rutherford’s but electron orbits are quantized

Answer 9

niels bohr

Question 10

similar to Bohr’s but electrons occupy regions known as orbitals instead of quantized orbits

Electrons are never found in a single location due to the wave-like properties of electrons

The probability of interacting with a specific electron can be found

Each orbital is defined by quantum numbers (n, l, ml, ms)

Each orbital can be occupied by a maximum of two electrons

Answer 10

atomic orbital model