Which state of matter has a fixed shape and a fixed volume?
Solid
For the process of melting, does energy need to be added or released from the system?
Added
What is the relationship between Carbon-12 and Carbon-13?
Draw a Bohr model of Nitrogen with a neutral charge. How many valence electrons does Nitrogen have?
5 valence electrons
What is the ideal gas law equation?
PV = nRT
Is boiling point an intensive or extensive property?
The atoms of a substance start moving faster. Did the kinetic energy of the atoms increase or decrease? What about the temperature?
Kinetic Energy: increases
Temperature: increases
Is this an example of fission or fusion?
Fission
Which of these ions has the greatest number of electrons?
O2-, K+, Mg2+, N3-
K+
For ideal gases, do volume and temperature have a direct or inverse relationship?
Direct.
PV = nRT. As V increases, T must also increase.
Which of the following is a physical change?
a. A piece of wood rotting after it gets wet
b. An ice cube melts when placed in the sun
c. An egg is cooked on a pan
d. A piece of paper starts burning after accidentally touching a candle
b. An ice cube melts when placed in the sun
A water bath is at 25oC. An object is placed in the water bath. After 10 minutes, the water bath is at 38oC. Did the object undergo an exothermic or endothermic reaction?
Exothermic
Name 3 uses and/or implications of nuclear chemistry outside of the classroom.
1. Nuclear Medicine (PET scans, radioimaging, radiotracing, radiation therapy)
2. Nuclear energy
3. Environmental presence of radioactive materials (Radon, for example)
List the following in order of increasing electronegativity: Sodium (Na), Nitrogen (N), Phosphorus (P), Fluorine (F).
Sodium (Na) < Phosphorus (P) < Nitrogen (N) < Fluorine (F)
What are the two rules/assumptions for ideal gases?
Molecules do not attract or repel each other, and have elastic collisions.
Molecules take up no volume, and are estimated as point particles.
Draw a model of an atom. Label all three subatomic particles, indicate their charge, and ensure that they’re in the correct location.
What is the difference between heat and temperature?
Temperature is a measure of kinetic energy of a substance
Heat is the transfer of energy between substances
What kind of decay occurs when Tb-159 decays into Gd-159? Write the equation for this decay?
Beta decay
15965Tb → 15964Gd + 0-1e
Which of the following pairs of elements will behave/react most similarly to one another?
a. Sodium (Na) & Magnesium (Mg)
b. Cobalt (Co) & Copper (Cu)
c. Fluorine (F) and Chlorine (Cl)
d. Silicon (Si) and Arsenic (As)
c. Fluorine (F) and Chlorine (Cl)
These elements are in the same period and have the same number of valence electrons.
Draw two gas particle diagrams: one for a gas at high temperature, and one for a gas at low temperature.
Lower temperature: shorter arrows
Higher temperature: longer arrows
Yesterday, Ms. Gelfand found a rock on her hik that had a mass of 7.45g. She takes a graduated cylinder filled with 10 mL of water, and drops the rock in the water. The graduated cylinder now reads 12.5 mL. What is the density of Ms. Gelfand’s rock? Include units!
2.98 g/mL
You are trying to determine the best material to use to make a hand warmer. You take a calorimeter made out of a styrofoam cup filled with water at 23oC, and place a 73g sample of CaCl2 inside. You record the temperature inside the styrofoam cup until you notice that the temperature stops changing – at 25.4oC. If the specific heat capacity of water is 4.18 J/goC, what is the change in energy for this reaction?
732.3 J
Q = mcΔT = 73g(4.18 J/goC)(25.4oC – 23oC) = 732.3 J
A (fake) element, Washingtonium, has the following percent abundances:
Washingtonium-86: 73%
Washingtonium-87: 22%
Washingtonium-88: 5%
What is the average atomic mass of Washingtonium?
86.32 amu
86 amu(.73) + 87 amu(.22) + 88 amu(.05) = 86.32 amu
Which of the following describes Sulfur (S) and Chlorine (Cl)? (can be just one, or a combination of multiple)
II. They have the same ionization energy
II. They have the same number of energy levels (shells)
III. They have the same number of valence electrons
II only. They have the same number of energy levels (shells).
What is the pressure of 4.2 moles of oxygen gas at 25oC that occupy a volume of 12.5 L? Give units!
8.2 atm
PV = nRT
P = nRT/V
((4.2 moles)(0.0821 (L*atm)/(K*mol))(298.15 K))/12.5L = 8.2 atm