Q&A Hero

Q: What is the atomic symbol for an element with 39 protons and 50 neutrons? A. B. C. D. E.

Q: Which of the following atoms contains the largest number of protons? A.231Pa B.238U C.232Th D.244Pu E.244Am

Q: Which of the following atoms contains the fewest protons? A.232Th B.231Pa C.245Pu D.238U E.232Pa

Q: What is the mass of chlorine-35 relative to carbon-12? A.0.657 B.0.522 C.1.52 D.2.92 E.23

Q: How many protons, neutrons, and electrons are in a nitrogen-15 atom? A.15 protons, 15 neutrons, 15 electrons B.15 protons, 7 neutrons, 15 electrons C.8 protons, 7 neutrons, 7 electrons D.7 protons, 8 neutrons, 7 electrons E.8 protons, 7 neutrons, 8 electrons

Q: How many protons, neutrons, and electrons are in a silver atom with a mass number of 108? A.47 protons, 47 neutrons, 61 electrons B.47 protons, 61 neutrons, 47 electrons C.61 protons, 47 neutrons, 47 electrons D.47 protons, 108 neutrons, 47 electrons E.61 protons, 108 neutrons, 61 electrons

Q: What is the mass number of an argon atom with 22 neutrons? A.2 B.18 C.22 D.40 E.39.95

Q: Which of the following statements is/are CORRECT?1. A hydrogen atom with 1 proton and zero neutrons is assigned a mass of exactly 1 atoms mass unit.2. 1 atomic mass unit is equivalent to 9.11 x 10-28 g.3. A carbon atom with 6 protons and 6 neutrons is assigned a mass of exactly 12 atomic mass units.A. 1 onlyB. 2 onlyC. 3 onlyD. 1 and 2E. 1, 2, and 3

Q: The atomic number of fluorine is ____. A.7A B.9 C.10 D.19 E.0

Q: Atomic number is the________ in the nucleus of an atom. A.number of electrons B.number of protons C.number of protons minus the number of neutrons D.sum of the number of electrons and neutrons E.sum of the number of neutrons and protons

Q: Rank the subatomic particles from least to greatest mass. A.electron mass = proton mass = neutron mass B.electron mass = neutron mass < proton mass C.electron mass = proton mass < neutron mass D.electron mass < proton mass < neutron mass E.electron mass < proton mass = neutron mass

Q: Which of the following statements concerning atomic structure is/are correct?1.Neutrons and electrons are found in space as a cloud around the nucleus.2.The nucleus contains all the positive charge of an atom.3.Electrons surround the nucleus and account for the majority of an atom's volume.A.1 onlyB.2 onlyC.3 onlyD.2 and 3E.1, 2, and 3

Q: The volume of space occupied by a carbon atom is 1.9 106 pm3. What is the volume of a carbon atom in cubic meters?A.1.9 10-30 m3B.1.9 10-21 m3C.1.9 10-12 m3D.1.9 106 m3E.1.9 1024 m3

Q: The volume of space occupied by a beryllium atom is 6.0 10-30 m3. What is this volume in units of nm3?A.6.0 10-57 nmB.6.0 10-21 nmC.6.0 10-12 nmD.6.0 10-3 nmE.6.0 106 nm

Q: Express 2.030 101 in standard notation. A.0.2030 B.2.030 C.2.03 D.20.3 E.20.30

Q: Express 0.00720 in exponential notation.A.7.20 103B.7.2 10-3C.7.20 10-3D.7.2 103E.7.2000 10-3

Q: Assume that an average and a standard deviation are calculated using a large number of measurements. A single data point has a(n) ____ chance of falling within plus and minus two standard deviations of the calculated average. A.50% B.68% C.83% D.95% E.100%

Q: Two students independently determine the volume of water delivered by a 10.00-mL pipet. Each student takes 8 measurements, then computes the average volume delivered and the standard deviation. The results are tabulated below. Average St. Dev. Student A 10.4 mL 0.7 mL Student B 10.00 mL 0.02 mL Which statement best describes the results? A.A: good precision, good accuracy. B: good precision, good accuracy. B.A: good precision, poor accuracy. B: poor precision, good accuracy. C.A: poor precision, good accuracy. B: good precision, poor accuracy. D.A: poor precision, poor accuracy. B: good precision, good accuracy. E.A: poor precision, poor accuracy. B: poor precision, poor accuracy.

Q: A student uses a balance to determine the mass of an object as 5.719 grams. The correct mass of the object is 5.586 grams. What is the percent error in the student's mass determination? A.2.38% B.0.133% C.13.3% D.74.3% E.97.7%

Q: Two electronic balances are tested using a standard weight. The true mass of the standard is 5.0000 g. The results of 5 individual measurements on each balance are recorded below. Balance A Balance B 5.2895 g 5.0001 g 5.1077 g 4.9998 g 4.6407 g 4.9999 g 4.8947 g 5.0002 g 5.0672 g 4.9999 g average mass = 5.0000 g 5.0000 gWhich statement best describes the results? A. A: poor precision, good accuracy. B: good precision, good accuracy.B. A: good precision, good accuracy. B: poor precision, good accuracy.C. A: good precision, good accuracy. B: good precision, poor accuracy.D. A: poor precision, good accuracy. B: good precision, poor accuracy.E. A: good precision, poor accuracy. B: poor precision, good accuracy.

Q: How many nutritional calories are equivalent to 1150 kJ? A.0.10 Cal B.1.15 Cal C.275 Cal D.4.8 103 Cal E.3.6 10-3 Cal

Q: How many joules are equivalent to 450 calories?A.0.45 JB.4.5 102 JC.9.3 10-3 JD.1.9 103 JE.4.5 105 J

Q: Which of the following statements is/are CORRECT?A joule is defined as the energy required to change 1.00 g of water from 14.5 C to 15.5 C.One calorie (c) equals 4.184 J, where the joule (J) is the SI unit of energy.A calorie (c) is equal to 1000 dietary calories (C).A.1 onlyB.2 onlyC.3 onlyD.1 and 2E.1, 2, and 3

Q: Which of the following volumes are equivalent to 75 mL?1. 0.75 cm32. 7.5 ´ 10"23. 0.0075 LA.1 onlyB.2 onlyC.3 onlyD.1 and 2E.1, 2, and 3

Q: Light with a wavelength of 1.5 10"8 m is in the x-ray region of the electromagnetic spectrum. What is the wavelength of this light in picometers? A.1.5 10"80 pm B.1.5 10"20 pm C.1.5 10"1 pm D.1.5 104 pm E.1.5 107 pm

Q: The wavelength of light emitted from a particular red diode laser is 651 nm. What is the wavelength in meters? A.6.51 1011 m B.6.51 10"2 m C.6.51 10"4 m D.6.51 10"7 m E.6.51 10"9 m

Q: The radius of an potassium atom is 0.227 nm. What is the radius in millimeters? A.2.27 10"9 mm B.2.27 10"8 mm C.2.27 10"7 mm D.2.27 10"6 mm E.2.27 10"4 mm

Q: Which of the following is the largest volume? A.5.0 102 cm3 B.5.0 10"4 L C.5.0 103 mL D.5.0 10"1 L E.5.0 105 mL

Q: Which of the following is the smallest mass? A.1.5 108 pg B.1.5 106 ng C.1.5 103 mg D.1.5 10"1 mg E.1.5 10"5 g

Q: The boiling point of ammonia is "33.3 C. What is this temperature in kelvin?A.-306.5 KB.-33.3 KC.239.9 KD.306.5 KE.331.5 K

Q: The boiling point of liquid oxygen is 90.2 K. What is this temperature in celsius?A.-208.0 CB.-183.0 CC.90.2 CD.194.4 CE.363.4 C

Q: Tin melts at 232.0 C. What is this temperature in kelvin?A.-41.2 KB.232.0 KC.449.6 KD.505.2 KE.530.2 K

Q: Which method is correct for converting kelvin to Celsius? A. B. C. D. E.

Q: Which one of the following is not an SI base unit? A.liter B.mole C.calorie D.ampere E.second

Q: The SI unit of temperature is the ____. A.kelvin B.calorie C.fahrenheit D.ngstrom E.kilocalorie

Q: The SI base unit of length is the ____. A.Newton B.liter C.meter D.cm3 E.ngstrom

Q: Significant figures allow us to estimate uncertainty in calculated values. In some circumstances, following significant figure rules can lead to estimates of uncertainty that are too high or low. This is the case for the mathematical expression below. 99 1.02 = 100.98 Following the rules governing significant figures in multiplication, the answer can be rounded to 1.0 102. What is wrong with rounding this answer to two significant figures?

Q: What is the difference between the accuracy of measurements and the precision of measurements?

Q: Assuming the density of water is 1.00 g/cm3, the mass of 1.0 cubic meter (m3) of water is ________ grams.

Q: At 25 C, a bottle contains 2.00 L of water in its liquid state. What is the volume of the water after it freezes (at 0 C)? The densities of liquid water and ice are 0.997 g/mL and 0.917 g/mL, respectively. A.1.09 L B.1.84 L C.2.00 L D.2.17 L E.2.19 L

Q: You can identify a metal by carefully determining its density. A 7.969 g cylinder of an unknown metal is 2.00 cm long and has a diameter of 0.755 cm. What is a possible identity of the element? (Volume = pr2h) A.silver, 10.5 g/cm3 B.iridium, 22.4 g/cm3 C.gold, 19.3 g/cm3 D.lead, 11.4 g/cm3 E.nickel, 8.90 g/cm3

Q: You can identify a metal by carefully determining its density. A 29.51 g sample of an unknown metal is 1.50 cm long, 2.50 cm wide, and 1.00 cm thick. What is a possible identity of the element? A.nickel, 8.90 g/cm3 B.aluminum, 2.70 g/cm3 C.silver, 10.5 g/cm3 D.iron, 7.87 g/cm3 E.chromium, 7.20 g/cm3

Q: The mass of a 16.0 ounce soda can filled with mercury is 6.39 kg. What is the density of mercury? Assume the can has no mass. (1.00 oz = 29.6 mL, 1.00 mL = 1.00 cm3) A.3.45 g/cm3 B.21.6 g/cm3 C.13.5 g/cm3 D.399 g/cm3 E.1.18 104 g/cm3

Q: The density of ice at 0 C is 0.917 g/mL. What is the volume of 125 g of ice? A.0.00734 mL B.115 mL C.124 mL D.126 mL E.136 mL

Q: A barometer is filled with a cylindrical column of mercury that is 76.0 cm high and 1.000 cm in diameter. If the density of mercury is 13.53 g/cm3, what is the mass of mercury in the column? (Volume = pr2h) A.0.227 g B.4.41 g C.808 g D.1.03 103 g E.3.23 103 g

Q: If 12 ounces of a liquid has a mass of 317 g, what is the density of the liquid in grams per cubic centimeter? (29.6 cm3 = 1.00 oz.) A.0.0013 g/cm3 B.0.89 g/cm3 C.1.1 g/cm3 D.0.0013 g/cm3 E.130 g/cm3

Q: If the density of nitrogen in air is 0.87 g/L, what mass (in kg) of nitrogen is contained in a room with dimensions of 4.0 m 3.5 m 2.4 m?A.29 kgB.39 kgC.2.6 10-2 kgD.2.9 104 kgE.26 kg

Q: Calcium carbonate, or limestone, is relatively insoluble in water. At 25 C, only 5.8 mg will dissolve in 1.0 liter of water. What volume of water is needed to dissolve 5.0 g of calcium carbonate?A.4.6 10-3 LB.3.0 10-2 LC.1.4 102 LD.3.4 102 LE.8.6 102 L

Q: Silver chloride (AgCl) is relatively insoluble in water. At 25 C, 1.3 103 L of water is needed to dissolve 2.5 g of AgCl. What mass (in milligrams) of AgCl will dissolve in 1.0 L of water?A.1.9 10-3 mgB.1.9 mgC.0.52 mgD.520 mgE.1.9 10-6 mg

Q: If a gallon (3.78 L) of latex paint can cover 365 ft2 of the surface of a wall, what is the average thickness of one coat of paint (in millimeters)? (12 in = 1 ft, 2.54 cm = 1 in)A.1.11 10-1 mmB.2.83 10-1 mmC.4.64 10-1 mmD.4.89 10-1 mmE.3.40 mm

Q: The speed of light in a vacuum is 3.00 108 m/s. What is the speed of light in units of kilometers per hour?A.1.20 10-2 km/hrB.8.33 101 km/hrC.8.33 107 km/hrD.1.08 109 km/hrE.1.08 1015 km/hr

Q: The speed of sound at one atmosphere of pressure is 0.214 miles per second. What is the speed of sound in units of meters per second? (1 km = 0.621 mile) A.133 m/s B.345 m/s C.478 m/s D.4.46 104 m/s E.4.78 105 m/s

Q: If the fuel efficiency of an automobile is 32 miles per gallon, what is its fuel efficiency in kilometers per liter? (1 km = 0.621 mile, 1.000 L = 1.057 quarts, 4 quarts = 1 gallon) A.5.3 km/L B.14 km/L C.20 km/L D.75 km/L E.2.0 102 km/L

Q: A cylinder has a radius of 2.38 mm and a height of 175 mm. Calculate the volume of the cylinder in liters. (Volume = pr2h)A.3.11 10-3 LB.3.11 10-2 LC.0.311 LD.3.11 LE.3.11 103 L

Q: The volume of an object is 8.12 10-3 m3. Calculate the volume in cubic feet. (2.54 cm = 1.00 inch, 12.0 inches = 1.00 foot)A.2.87 10-7 ft3B.0.287 ft3C.0.0266 ft3D.2.30 10-4 ft3E.8.74 10-2 ft3

Q: The dimensions of a box are 1.2 feet by 0.50 feet by 0.75 feet. Calculate the volume of the box in cubic centimeters. (2.54 cm = 1.00 inch, 12.0 inches = 1.00 foot) A.14 cm3 B.47 cm3 C.306 cm3 D.418 cm3 E.1.3 104 cm3

Q: A cube has dimensions of 0.60 meters on each side. What is the volume of the cube in liters? A.1.8 L B.1800 L C.0.22 L D.22 L E.220 L

Q: The volume of a carbon atom is 1.9 10-30 m3. What is the radius of the atom in picometers? The volume of a sphere is (4/3)pr3.A.77 pmB.520 pmC.770 pmD.3.0 102 pmE.52 pm

Q: What is the correct answer to the following expression?7.4576 10-2 + 4.11 10-5 + 6 10-4 =A.7. 10-2B.7.5 10-2C.7.52 10-2D.7.522 10-2E.7.5217 10-2

Q: What is the correct answer to the following expression: 5.23 10-7 - 8.30 10-9?A.5 10-7B.5.2 10-7C.5.15 10-7D.5.147 10-7E.5.1470 10-7

Q: What is the correct answer to the following expression: (995 + 8) 0.47015? Carry out the addition operation first. A.500 B.470 C.472 D.471.6 E.471.56

Q: What is the correct answer to the following expression: (205.18 - 197.3) 6.226? Carry out the subtraction operation first.A.1B.1.3C.1.27D.1.266E.1.2657

Q: Round 0.00680483 to 3 significant figures. A.0.00 B.0.007 C.0.00680 D.0.006804 E.0.006805

Q: What is the correct number of significant figures in 0.000620? A.2 B.3 C.4 D.6 E.7

Q: An electronic balance is used to determine that a sample has a mass of 4.94691 g. If the balance's precision is 0.02 mg, what is the correct number of significant figures for this measurement? A.2 B.3 C.4 D.5 E.6

Q: Convert 0.490 ng to milligrams and express the answer in scientific notation using the correct number of significant figures.A.4.90 10-5 mgB.4.90 10-7 mgC.4.9 10-mgD.0.490 10-8 mgE.0.490 10-7 mg

Q: Convert 8.900 10-8 meters to nanometers and express the answer in standard notation using the correct number of significant figures.A.89 nmB.89.0 nmC.89.00 nmD.8.90 nmE.0.8900