hw questions - chapter 1, 2, 3.1-3.2

Question 1

what are some characteristics of a law? can they be falsified?

Answer 1

• predictive of natural phenomena
• unifying concept for natural phenomena
• often a mathematical relationship
• relates observable quantities to physical constants

can be falsified through contradictory empirical data

Question 2

a theory is another word for a ______

Answer 2

model

Question 3

a homogeneous mixture is also called a ________

Answer 3

solution

Question 4

the uncertainty in the measurement 13.560 mg is

Answer 4

+/- 0.001mg

Question 5

formula to convert C to F

Answer 5

°C=(°F − 32) × 5/9
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Question 6

which 2 postulates of dalton’s atomic theory are not true?

Answer 6

• all atoms of a given element are identical
• atoms are indestructible

later discovered that atoms can be of the same element but w/ different masses (isotopes) and that some atoms decay by loss of helium nucleus, and some atoms can be split by nuclear fission

Question 7

law of definite proportions (aka law of constant composition)

Answer 7

regardless of method of preparation, a given compound will always consist of the same elements in the same proportion

Question 8

what did the Millikan oil drop experiment directly determine?

Answer 8

the charge of the electron

Question 9

cathode rays are composed of what fundamental particle?

Answer 9

electrons (bc they are negatively charged)

Question 10

alpha particles

Answer 10

positively charged particles of radiation emitted from the decay of radioactive substances

Question 11

energy of a photon is __________ proportional to frequency, and ___________ proportional to wavelength

Answer 11

directly, inversely

Question 12

relationship b/w wavelength and frequency

Answer 12

inversely related

Question 13

which color (frequency) of light travels the fastest in a vacuum?

Answer 13

the speed of light is constant in a vacuum and all colors of light travel at the same speed

Question 14

neutral atoms of all isotopes of a given element have the same

Answer 14

number of electrons

Question 15

mass number

Answer 15

sum of neutrons and protons (different from atomic #, which is just the number of protons)

Question 16

if the frequency of an electromagnetic wave decreases, the amplitude will ____________

Answer 16

stay the same

amplitude is independent of frequency

Question 17

in the photoelectric effect, if the intensity of light shone on a metal increases, what will happen?

Answer 17

there will be more electrons ejected

Question 18

which scientist surmised the scientific principle that the position & momentum of an electron cannot be known simultaneously with a high degree of accuracy?

Answer 18

Heisenberg

(the uncertainty principle)
(typically attributed to Schrödinger but he worked amongst many other scientists to develop quantum mechanical theory)

Question 19

how many electrons are in the n=1 shell in a neutral fluorine atom?

Answer 19

2

Question 20

cations are always ________ than the neutral atom they are derived from and anion are always __________ than the neutral atom.

Answer 20

smaller; larger

Question 21

which element has the symbol Sn?

Answer 21

tin

Question 22

rare-earth (lanthanide) elements are elements with the atomic numbers _______

Answer 22

57-71

Question 23

transition metals lose electrons from the _______________ first when they become cations

Answer 23

highest n level