Variable Identification
Identify the IV, DV, and control: The higher the temperature of the air in the oven, the faster a cake will bake.
IV: Oven air temperature
DV: Bake time
Control: Size of cake, type of cake, type of oven
Convert 100 mm into inches.
(1 inch = 2.54 cm)
(1 cm = 10 mm)
3.94 inches
Protons:
Electrons:
Neutrons:
Protons: positive
Electrons: negative
Neutrons: neutral
What is an isotope?
Variations of an element with the same number of protons, but different number of neutrons, therefore different masses.
Which bond is created by transferring electrons rather than sharing?
Ionic bonds
Identify the IV, DV, and control: The amount of pollution produced by cars was measured for cars using gasoline containing different amounts of lead.
IV: Amount of lead
DV: Amount of pollution
Control: Type of car
Convert 32 years into hours.
2.8 x 10^5 hr
What two subatomic particles contribute the most to an atom's mass?
Protons + Neutrons = Mass
Atomic Mass = (% abundance * mass) + (% abundance * mass)
**with the percentages in decimal form
What is the molecular formula for lithium sulfide?
Li2S
Four groups of rats are first massed and then fed identical diets except for the amount of vitamin A they receive. Each group gets a different amount. After 3 weeks on the diet, the rats’ masses are measured again to see if there has been a decrease. Identify the IV, DV, and control.
IV: Amount of vitamin A
DV: Rats' masses
Control: Diet
Convert 27 km/hr into m/s.
7.5 m/s
An element has 20 protons, 20 electrons, and 22 neutrons. What is its mass? Include units.
42 amu
Sulfur has two isotopes, S-32, which is 98.00% of the sulfur and S-35, which is 2.00% of the sulfur.
What is the exact atomic mass of sulfur?
32.06 amu
What is the name of the compound PCl3
Phosphorous trichloride
Identify the IV, DV, and control: Two groups of students were tested to compare their speed working math problems. Each group was given the same problems. One group used calculators and the other group computed without calculators.
IV: Use of calculator
DV: Math problem completion speed
Control: Same problems
Convert 420 ft/sec into miles/hr.
(1 mile = 5280 ft)
283.36 mi/hr
An atom has 10 protons, 12 electrons, and 11 neutrons. Is this a cation or anion? What is its charge?
Anion: -2 charge
A mystery element has three isotopes. One with a mass of 28.1 and abundance of 35%, the second with a mass of 29.5 and abundance of 38%, and the third with a mass of 31 and abundance of 27%. What is the atomic mass of this element?
29.415 amu
Write the name of Fe2O3
Iron (III) oxide
Identify the IV, DV, and control: Homer notices that his shower is covered in a strange green slime. His friend Barney tells him that coconut juice will get rid of the green slime. Homer decides to check this out by spraying half of the shower with coconut juice. He sprays the other half of the shower with water. After 3 days of "treatment" there is no change in the appearance of the green slime on either side of the shower.
IV: Spray used
DV: Amount of slime removed
Control: Amount of spray
Convert 120 ft/min into km/hr.
(1 mile = 5280 ft)
(1 hour = 60 min)
(1 km = 0.62 mile)
2.2 km / hr
An atom of sulfur has a charge of -2 and mass of 32. How many protons, neutrons, and electrons does it have?
Protons: 16
Neutrons: 16
Electrons: 18
Phosphorus has two isotopes, P-32 and P-30. The experimentally determined mass of phosphorus is 30.974 amu. What are the percentages of the two isotopes?
P-32: 48.7%
P-30: 51.3%
Given that the polyatomic ion formula for acetate is C2H3O2 and has a charge of -1, write the molecular formula for aluminum acetate.
Al(C2H3O2)3