Measuring Up
History of Matter
Misc.
Solving
100
What is the SI unit for the number of particles in a substance?
Mole
100
Who discovered the neutron?
James Chadwick
100
What is the number of protons in a nucleus?
Atomic number
100
Convert 54 K to μK.
5.4 * 107 μK
200
What is a comparison of an unknown quantity to a known standard unit?
Measurement
200
Who was the first to make models on the atom based on experiments?
John Dalton
200
How many significant figures in 0.0020 Cd?
Two
200
Add 40 mol to 3.2 mol
40 mol
300
What are derived units?
Combinations of the fundamental units
300
What was Democritus known for?
Credited as being the first to believe that matter is made of individual particles
300
What is the candela?
The SI unit of light intensity
300
Multiply 85.2 m by 4.1 m.
349.32 m2
400
What is the difference between accuracy and precision?
Accuracy - how close a measured value is to the expected or accepted value of the dimension being measured
Precision - the exactness of a measurement or a measuring instrument
400
How was the nucleus discovered (and its size)?
Gold foil experiment
Alpha particles were shot at a thin gold foil
If Thompson’s model was correct, all of the alpha particles should have gone straight through the atom because of how evenly spaced the protons are
Instead, most of the particles went straight through, but some were deflected at wide angles, and some were ricoted right back
Indicates that most of the atom is empty space
400
What is the law of multiple proportions?
Whenever a fixed amount of one element could combine with different masses of another element, the masses of elements could only combine in a ration that could be reduced to small, whole number ratios
400
Write the amount of protons, neutrons, and electrons in
17 protons
18 neutrons
17 electrons
500
Give the power of ten for all of these prefixes: M, k, d, c, m, μ, n, and p.
Mega (M) = 106
Kilo (k) = 103
Deci (d) = 10-1
Centi (c) = 10-2
Milli (m) = 10-3
Micro (μ) = 10-6
Nano (n) = 10-9
Pico (p) = 10-12
500
List five conclusions of Dalton's experiments.
All matter is made of atoms
Atoms are indivisible
The atoms of an element are all alike
The atoms of one element are different from the atoms of all other elements, especially their masses
Atoms combine chemically in small, whole number ratios
500
What is a unified atomic mass unit?
1/12 the mass of a carbon-12 atom
500
There are three main isotopes of oxygen. Oxygen-16 (15.995 u) has an abundance of 99.8%. Oxygen-17 (16.999) has an abundance of .0380%. Oxygen-18 (17.999) has abundance of .205%.
16.065 u