1 and 2
5 and 7
3 and 6
9 and 10
11 and 15
100
Which force is responsible for holding the nucleus of an atom together?
Strong Force
100
A student drops a white tablet into a glass of water, producing carbon dioxide gas. This is a demonstration of
A chemical reaction
100
Why do blacksmiths place metal into a fire before pounding it into shape to form horseshoes?
The heat increases electron activity, which increases the malleability of the metal.
100
After a soccer game, Brittany sat under a fan because she was hot. Under the fan, she felt cooler than before. Which explains why Brittany felt cooler under the fan?
The evaporation of sweat absorbs heat from the skin.
100
A type of juice has a sour taste and turns a piece of litmus paper red. Which term describes the juice?
acidic
200
Which part of an atom creates most of the atom’s volume?
Electron
200
Where in the periodic table would shiny, malleable materials used in making jewelry be found?
Group 11 (1B)
200
Electronegativity values for elements in Group 1A are much lower than the values for elements in Group 7A. What type of bond forms if an element from Group 1A bonds with an element from Group 7A?
ionic bond
200
Scientists developed a device capable of lowering temperatures in order to slow molecular motion to almost a complete stop. Which of these temperatures is theoretically able to make this happen?
0 K
200
What is the pH for a solution that has an
concentration of
6
300
The electrical charge of the nucleus of an atom is +12. How many electrons does the atom have in its neutral state?
12
300
Iron (Fe) is an effective conductor of heat and electricity. Which other element is most likely to have similar conductivity? (K, Ni, Br, or Kr)
Ni
300
What is the chemical formula of the phosphate ion?
PO4^3-
300
Nitrogen and hydrogen react to produce ammonia.
How many grams of hydrogen are needed to produce 15.0 mol of ammonia if the reaction goes to completion?
45g H2
300
A sample of helium gas is stored in a tank at 18 atm and 20°C. How do these conditions compare to the conditions of a gas at STP?
higher pressure and higher temperature than STP
400
The equation below represents the radioactive decay of a gold isotope.
174/79 Au -> 170/77 Ir + ?
Alpha Particle
400
Solid chromium(II) reacts with oxygen gas to form solid CrO. What is this type of reaction?
synthesis
400
What is the chemical formula of magnesium fluoride?
MgF2
400
A chemist mixed 50 mL of 0.060 M HCl and 50 mL of 0.060 M NaOH in a calorimeter. Both solutions had a starting temperature of 25°C and a density of 1.00 g/mL. The solution reached a maximum temperature of 34°C during the reaction. About how many kilojoules of energy (q) did the reaction release? (Cwater = 4.18 J/g•°C)
3.8 kJ
400
A sample of 0.02 mol of oxygen has a temperature of 399K and a volume of 5.00 L. What is its pressure?
(Ideal gas law: 
, 
)
0.13 atm
500
Potassium-40 is a radioactive isotope that has a half-life of 1.25 billion years. The daughter isotope of potassium-40 is argon-40. What is the approximate age of an igneous rock that has a 1:3 ratio of potassium-40 atoms to argon-40 atoms?
2.5 billion years
500
What has to occur before an atom in its ground state can emit a photon?
excitation of an electron to a higher energy state
500
Based on the positions of the elements on the periodic table, what is the chemical formula of aluminum sulfide?
Al2S3
500
The chemical equation represents a reaction between ammonia and oxygen to form nitrogen monoxide and water.
What is the limiting reagent when a 2.00 g sample of ammonia is mixed with 4.00 g of oxygen?
O2
500
Magnesium hydroxide and sodium hydroxide are both strong bases. The pH of a saturated solution of sodium hydroxide is greater than 14. The pH of a saturated solution of magnesium hydroxide is about 10.2. Why do the solutions have different pH values?
Sodium hydroxide is much more soluble in water than magnesium hydroxide.