Definitions
What is matter?
Matter is anything that has mass or takes up space.
(From lecture slides)
What is an electron, who discovered it, and how?
JJ Thompson and the cathode ray experiment.
(From lecture slides)
What is an isotope?
Isotopes are atoms of the same element with
different masses due to different numbers of neutrons.
(From lecture slides)
Name this binary compound: CCl4
Carbon TETRAchloride
(From lecture slides)
Convert 18.07 meters into feet.
- 100 cm = 1 meter
- 1 inch = 2.54 cm
59.28 feet
(Modified lecture slide problem)
Fill in the blanks:
Atoms of one element differ in " " from atoms of all other " ".
Atoms of one element differ in "properties" from atoms of all other "elements."
(Dalton's 3rd postulate of The Atomic Theory, from lecture slides)
Before the discovery of the nucleus, what did the prevailing model of the atom look like?
As proposed by JJ Thompson, the prevailing model of the atom before the discovery of the nucleus was referred to as the "Plum pudding" model because it depicts negative electrons floating in a sphere made of a cloud of positive mass.
(From lecture slides)
What is the difference between Atomic Number and Atomic Mass?
Atomic number corresponds to the number of protons of an atom--which never changes--and also correlates to the order in which they present on the periodic table. Atomic mass is the sum of protons and neutrons--which varies between isotopes.
(From lecture slides)
Name this binary compound: PCl5
Phosphorus PENTAchloride
The average speed of a carbon dioxide molecule in the stratosphere of the Earth travels at a speed of 1651 m/s. Convert into miles per hour.
(Not fact checked)
- 1 km = 1000 meters
- 1 mile = 1.6093 km
3693 miles per hour
(Modified lecture slide problem)
What is The Law of Constant Composition?
The Law of Constant Composition (or Law of Definite Proportions) states that the elemental composition of a pure substance never changes. (ex. Aspirin)
(From lecture slides)
What does it mean for something to be a cation?
Atoms that gain a positive charge calculated by subtracting the number of electrons from the number of protons.
(From lecture slides)
What is average mass and why is it necessary?
Average mass is calculated from the
isotopes of an element weighted by
their relative abundances. This is because in the real world we use large amounts of atoms and molecules.
(From lecture slides)
Name this binary compound: N2O
Dinitrogen monoxide (or laughing gas)
A toy car is moving at a speed of 3.5 cm/s, what is the toy car's speed in kilometers per hour?
- 1 meter = 100 cm
- 1 km = 1000 m
0.13 kilometers per hour
What is the Law of Conservation of Mass?
The total mass of substances present at
the end of a chemical process is the
same as the mass of substances
present before the process took place.
(From lecture slides)
What does it mean for something to be an anion?
Atoms that gain a negatuve charge calculated by subtracting the number of electrons from the number of protons.
(From lecture slides)
Where are nonmetals located on the periodic table?
Nonmetals are located on the right side of the periodic table--right of the "staircase"--except for hydrogen, which is on the left side above the 1A group.
(From lecture slides)
If the base/most common oxyanion for Chloride is named Chlorate, ClO3−, what is the name of ClO2−? (Hint: one less oxygen)
Chlorite. Oxyanions ending in "-ate" are in the most common/base form. If you remove an oxygen, the ending changes to "-ite."
(From lecture slides)
A tank holds 12.5 gallons of water. What is the mass of the water in kilograms, assuming the density of water is 1.00g/mL?
- 1 gallon = 3.78541 L
47.3 kg
What is the Law of Multiple Proportions?
The law of multiple proportions states that when two
elements react to form more than one compound, a
fixed mass of one element will react with masses of
the other element in a ratio of small, whole numbers.
(From lecture slides)
Describe The Nuclear Atom
After discovering the existence of the nucleus from the gold foil experiment, Ernest Rutherford proposed that the atom was mostly empty space with a hard, concentrated sphere of mass in the middle--the nucleus. Unlike the Plum pudding model, it postulates that electrons orbit around the nucleus.
(From lecture slides)
What are the seven, naturally diatomic elements?
Hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, and Iodine.
If the base/most common oxyanion for Chloride is named Chlorate, ClO3−, what is the name of ClO4−? (Hint: one more oxygen)
Perchlorate. This oxyanion as the most number of oxygens in the chloride series, so we give it the prefix "per-" and ending "-ate." For reference, the entire oxyanion chloride series from least number of oxygen to most is hypochlorite, chlorite, chlorate, and perchlorate.
(From lecture slides)
A car can travel 15.7 miles per gallon of gas. Convert to kilometers per milliliter of gas.
- 1 mile = 1.607 km
- 1 gal = 3.78541
0.00667 km/mL