chemistry chapter 3 and 4

Question 1

john dalton

Answer 1

featureless sphere billiard ball

Question 2

jj thompson

Answer 2

plum pudding model discovered electrons cathode ray tube

Question 3

ernest rutherford

Answer 3

discovered small pos nucleus gold foil atoms are mostly empty space

Question 4

james chadwick

Answer 4

found neutrons

Question 5

isotopes

Answer 5

same number of protons and different number of neutrons

Question 6

radioisotopes

Answer 6

unstable emit gamma rays and alpha or beta particle

Question 7

light

Answer 7

electromagnetic radiation measured in wavelengths

Question 8

photoelectric effect

Answer 8

electrically charged particles are released from or within a material when it absorbs electromagnetic radiation

Question 9

max plank

Answer 9

heated blackbodies found a quantium of energy and he found that light has similar properties to particle

Question 10

einstein

Answer 10

explained the photoelectric effect and said that photons are a unit of light energy

Question 11

what was the issue with rutherfords model

Answer 11

rutherfordss model was incorrect becase if that was true the negative electrons wouldve creased kinto the positivve nucleus

Question 12

neils bohr

Answer 12

viewed hydrogen through a spectroscope saw bright coloured lines and proposed that electrons were moving at fixed distances from the nuclesu bohrs model only worked for hydrogen

Question 13

schrodinger

Answer 13

developed a wave equationthat could calculate electron energy levels electrons were now described as existing in a 3D space called an orbital

Question 14

heinsenberg

Answer 14

he came up with the uncertainty principle because if you try and find where an electron is it chnages its position we can only describe the probability of where an electron is

Question 15

orbitals vs orbits

Answer 15

ORBITALS 
quantum mechanics 
2e- 3D
distance from nucleus varys 
no set path

ORBITS
bohr
2ne- 2D
distance from nucleus is fixed 
path is elliptical or circular

Question 16

what is the principle quantum number

Answer 16

(n) corresponds to the energy level (shell) it is a whole # 1 2 3

Question 17

what is the secondary quantum number

Answer 17

(l) describes the shape (s,p,d,and f) subshells in n=1 only s orbitals exist, in n=2 there can only be s and p orbitalsin n=3 there can be s p and d and in n=4 there can be spd adn f orbitals

Question 18

the magnetic quantum number

Answer 18

(Mi) describes the orientation of the orbital ranges from +l to -l
s orbitals (l=0)ml can only be 0
p orbitals (I=l)  ml can be +1 0 -1
d orbitals (l=2) ml can be +2 +1 0 -1 -2
f orbitals (l=3) ml can be +3 +2 +1 0 -1 -2 -3

Question 19

the spin quantum number

Answer 19

(ms) relates to the spin of the e- tow electrons pared withitn the same orbital lmust have opposite spins (pauli exclusion principle) must be either +1l2 or -1l2

Question 20

the aufbau principle

Answer 20

e must fill orbitals in order of increasing energy starting form nearest to the nucleus

Question 21

pauli exclusion principle

Answer 21

two electrons paired within the same energy level must have opposite spins

Question 22

hunds rule

Answer 22

you must half fill each orbital w parallel spins before pairing electrons with opposite spins

Question 23

ferrromagnetism

Answer 23

very strong magnetism exhibited by materials that contain nickel, iron, cobalt they have several unpaired e-

Question 24

paramagnetism

Answer 24

weak attraction of a substance to a magnet for individual atoms such as aluminium and platinum due to their unpaired e- all having the same spin which generates a weak magnetic feild

Question 25

laser

Answer 25

e- are stimulated to higher energy states then release radiation when they return to ground state this release of photons trigger other atoms to do the saem increasing the intensity of the light mirrors are used to reflect causing them to collide with atoms and release more photons

light amplification by simulated emission of radiation

they produce an intense beam of light in a single wavelength the waves are parallel and coherent can transfer a great deal of energy causing burns and blindness

Question 26

MRI

Answer 26

magnetic resonance imaging uses a strong magnetic fe3ild to cause magnetic fields of hydrogen atoms in the human body to align in the same direction and radio waves are then applied and cause the magnetic fields to flip int the opposite direction a scanner detects these changes and a computer converts them into a 3D image soft tissues including muscles organs and the brain can be seen.

Question 27

xray

Answer 27

involve electrons being acceletated to high velocities adn collide with a terget material such as tungsten casuign its elecyrons to also jump to a higher energy level when the electrons return to their ground state very high energy photons called xrays are emitted bones absorb x rays producing a shadow image on the film

Question 28

ionic bond

Answer 28

an electrostatic attraction between oppositely charged ions (metals lose electrons to form positive ions nonmetals gain electrons to form negative ions)
these attractions form a crystal lattice structure made of several oppositely charged ions the smalled ration represented by the chemical formula

Question 29

covalent bonding

Answer 29

when two nonmetals share electrons the shared pair of electrons forms a covalent (intermolecular bond the bond forms at an optimal distance to minimize their energy and minimize their repulsion