Q&A Hero

Q: A beam is under stress when it carries a load. The part of a beam where no tension or compression occurs is the A) upper or lower flange. B) neutral layer. C) neither of these

Q: A horizontal wooden beam sags a bit when supported at its ends. In between the top and bottom surfaces is a region of A) tension. B) compression. C) neither of these

Q: When a load is placed on the middle of a horizontal beam supported at each end, the top part of the beam undergoes A) tension. B) compression. C) either of these D) none of these

Q: When a load is placed on the middle of a horizontal beam supported at each end, the bottom part of the beam undergoes A) tension. B) compression. C) either of these D) none of these

Q: An un-stretched hanging spring is 50 cm long. Suspending a 100-N block from it increases its length to 60 cm. Adding another 100-N block makes the spring's length A) 60 cm. B) 70 cm. C) 80 cm. D) 100 cm. E) 120 cm.

Q: A weightless spring is stretched 10 cm by a suspended 1-kg block. If two such springs are used to suspend the block, one spring above the other, to effectively provide one double-length spring, then the total stretch of the double-length spring will be A) 5 cm. B) 10 cm. C) 20 cm. D) 30 cm. E) none of the above

Q: A spring is stretched 10 cm by a suspended 1-kg block. If two such springs side-by-side are used to suspend the 1-kg block, each spring will then stretch A) 5 cm. B) 10 cm. C) 20 cm. D) 30 cm. E) none of the above

Q: A strong spring is stretched 10 cm by a suspended block. If the block's weight is doubled, the spring will stretch to A) 15 cm. B) 20 cm. C) 40 cm. D) its elastic limit.

Q: Which ball will bounce higher off a hard surface? A) a common rubber ball B) a steel ball C) both the same

Q: Which ball is more elastic? A) a common rubber ball B) a steel ball C) both the same

Q: A metal block has a density of 5000 kg per cubic meter and a mass of 15,000 kg. What is its volume? A) 0.33 cubic meters B) 3 cubic meters C) 5 cubic meters D) 15 cubic meters E) none of the above

Q: A metal block has a density of 5000 kg per cubic meter and a volume of 2 cubic meters. What is the block's mass? A) 1000 kg B) 2500 kg C) 5000 kg D) 10,000 kg E) none of the above

Q: An iron block in a furnace is heated and consequently expands, which means that its density is A) less. B) the same. C) more.

Q: A metal block has a mass of 5 grams and a volume of 1 cubic centimeter. A piece of the same kind of metal with a volume of 2 cubic centimeters has a density of A) 2.5 g/cm3. B) 5 g/cm3. C) 10 g/cm3.

Q: The density of a 2-cubic meter block of mass of 1000 kg is A) 100 kg/m3. B) 200 kg/m3. C) 500 kg/m3. D) 1000 kg/m3. E) none of the above

Q: If you hold two objects that have the same weight density, then they A) may have unequal mass densities. B) have equal mass densities. C) are equal in weight.

Q: If the volume of an object were doubled while its mass remained the same, its density would A) be half. B) double. C) stay the same. D) be four times as great.

Q: If the mass of an object were doubled while its volume remained the same, its density would A) be half. B) double. C) stay the same. D) be four times as great.

Q: Compared to the volume of a kilogram of feathers, the volume of a kilogram of lead is A) less. B) more. C) the same.

Q: Compared to the density of a kilogram of feathers, the density of a kilogram of lead is A) less. B) more. C) the same.

Q: Which has the greater density? A) a cup-full of fresh water B) a lake-full of fresh water C) both the same D) need more information

Q: Compared to a bar of pure gold, the density of a pure gold ring is A) less. B) the same. C) slightly more. D) much more.

Q: When a chocolate bar is cut in half, its density is A) halved. B) unchanged. C) doubled.

Q: If a loaf of bread is compressed its A) density decreases. B) density increases. C) neither of these

Q: Which is the greater amount for medication measured by mass? A) 1 gram B) 1000 milligrams C) both the same

Q: The first evidence confirming the crystal structure of matter was A) the citing of experiments by Nobel Prize-winning scientists. B) testimonials by crystal-loving investigators. C) X-ray diffraction patterns.

Q: The crystals in matter are held together by A) cohesive forces. B) amorphous forces. C) electrical bonding forces. D) excess neutrons.

Q: The metal in a chunk of copper or iron is composed of A) crystals. B) non-crystalline fibers. C) amorphous particles. D) none of the above

Q: If a gram of antimatter meets a kilogram of matter, the amount of mass to survive is A) 1 gram. B) 999 grams. C) 1 kilogram. D) 1.1 kilogram.

Q: In our part of the universe, antimatter is A) non-existent. B) plentiful. C) short-lived. D) long-lived.

Q: If an astronaut landed on a planet composed of antimatter, there would be an explosion and the A) planet would annihilate. B) astronaut would annihilate. C) astronaut and an equal amount of planet antimatter would both annihilate.

Q: How many atoms are in this carbohydrate molecule, C6H12O6? A) 3. B) 14. C) 18. D) 24. E) none of the above

Q: What is the total number of individual atoms in a water molecule? A) one B) two C) three D) four E) none

Q: How many different kinds of elements are in a water molecule? A) one B) two C) three D) four E) none

Q: When oxygen and hydrogen gases combine, the result is A) water. B) methane. C) a noble gas.

Q: When carbon and oxygen atoms combine, energy is A) absorbed by the reaction. B) released by the reaction. C) not involved.

Q: Compared to the energy it takes to separate oxygen and hydrogen from water, the amount of energy released when they recombine is A) slightly more. B) slightly less. C) much more. D) much less. E) the same.

Q: A molecule has A) mass. B) structure. C) energy. D) all of the above E) none of the above

Q: Which of the following statements is true? A) a molecule is the smallest existing particle B) chemical elements are made up of about 100 distinct molecules C) molecules form atoms that determine chemical properties of a substance D) molecules are the smallest subdivision of matter that still retain a substance's chemical properties E) none of the above

Q: Which of the following is NOT a mixture? A) granite B) cake C) air D) beach sand E) none of the above

Q: Which of the following is NOT a compound? A) air B) ammonia C) water D) salt E) all are compounds

Q: The air in this room has A) mass. B) weight. C) energy. D) all of the above E) none of the above

Q: What is the molecular mass of a water molecule? A) 10 amu B) 12 amu C) 15 amu D) 18 amu E) none of the above

Q: A nucleon has a mass of about A) 1 amu. B) 1 atomic mass unit. C) both are the same. D) none of the above

Q: Mass number refers to the number of A) protons in the nucleus. B) neutrons in the nucleus. C) nucleons in the nucleus.

Q: An atomic mass unit (amu) is 1/12 the mass of A) an electron. B) a proton. C) a hydrogen atom. D) a carbon atom. E) a uranium atom.

Q: An ion and an isotope are A) very much one and the same B) very unlike C) opposites.

Q: An isotope is simply an atom that A) is electrically charged. B) has different numbers of neutrons for the same element. C) both of these D) neither of these

Q: Which contains more atoms? A) 1 kg of hydrogen B) 1 kg of iron C) both contain the same

Q: The electrical force is stronger between the nucleus and an inner electron for atoms of A) low atomic number. B) high atomic number. C) both of these D) neither of these

Q: Compared to the diameter of a zirconium atom (A = 40), the diameter of a mercury atom (A = is approximately A) four times as large. B) twice as large. C) the same size. D) one-half as large. E) one-quarter as large.

Q: Heavy atoms are not appreciably larger in size than light atoms because the nuclei of heavy atoms have more A) mass. B) electric charge. C) nucleons. D) all of the above E) none of the above

Q: Compared to the average size of a hydrogen atom, the average size of a helium atom is A) larger. B) smaller. C) about the same.

Q: A uranium atom is 238 times as massive as a hydrogen atom. Compared with the diameter of a hydrogen atom, uranium's size is A) slightly smaller. B) only slightly larger. C) is much larger, but less than 238 times as large.

Q: How many protons should be added to the nuclei of oxygen atoms so the resulting gas will glow red when an electric current is in it? A) 1 B) 2 C) 3 D) 4 E) none of the above

Q: Compared to the mass of a hydrogen atom, the mass of an oxygen atom is A) 8 times as great. B) 12 times as great. C) 16 times as great. D) appreciably more than 16 times as great.

Q: The chemical properties of matter are due mostly to their A) protons. B) electrons. C) neutrons.

Q: Heavier atoms are not proportionally larger than lighter atoms due to the greater number of protons A) pulling surrounding electrons into tighter shells. B) squeezed into tighter spaces. C) both of these D) none of these

Q: If a nitrogen atom and a slightly heavier oxygen atom have equal kinetic energies, which has the greater average speed? A) nitrogen B) oxygen C) both the same D) need more information

Q: If a nitrogen atom and a slightly heavier oxygen atom have equal average speeds, which has the greater kinetic energy? A) nitrogen B) oxygen C) both the same D) need more information

Q: One neutron added to a helium nucleus results in A) hydrogen. B) boron. C) lithium. D) beryllium. E) helium.

Q: A pair of helium nuclei fused together produces A) helium isotope. B) lithium. C) beryllium. D) carbon. E) iron.

Q: A pair of hydrogen nuclei fused together produces A) helium. B) lithium. C) beryllium. D) carbon. E) iron.

Q: To change mercury into gold, a pair of protons must be A) removed from the mercury nucleus. B) added to the mercury nucleus. C) either of these D) neither of these

Q: Two protons added to an oxygen nucleus produce A) heavy oxygen. B) fluorine. C) neon. D) sodium. E) nitrogen.

Q: Two protons removed from an oxygen nucleus result in A) nitrogen. B) carbon. C) helium. D) neon. E) positively charged oxygen.

Q: Which of these atoms has the greatest number of electrons? A) helium B) carbon C) iron D) gold E) uranium

Q: Which of these atoms has the greatest amount of electrical charge in its nucleus? A) helium B) carbon C) iron D) gold E) uranium

Q: Which of these has the greatest number of protons in its nucleus? A) gold B) mercury C) lead D) silver

Q: The volume of matter is due mostly to its A) protons. B) electrons. C) both of these

Q: The mass of matter is due mostly to its A) protons. B) electrons. C) both of these

Q: Which of the following elements has the most mass? A) hydrogen B) iron C) lead D) uranium E) all have the same mass

Q: Which of the following is an inert gas? A) Hydrogen B) Helium. C) Carbon D) Oxygen

Q: Which of the following is a gas? A) lithium B) carbon C) neon D) sodium

Q: The number of protons in a neutral atom is balanced by an equal number of A) electron shells that surround the nucleus. B) neutrons in the nucleus. C) orbital electrons. D) none of the above

Q: Atomic number refers to the number of A) protons in the nucleus. B) neutrons in the nucleus. C) nucleons in the nucleus.

Q: A force that determines the chemical properties of an atom is A) a friction force. B) a nuclear force. C) a gravitational force. D) an electrical force. E) none of the above

Q: Although solid matter is mostly empty space, we don't fall through the floor because A) atoms are constantly vibrating, even at absolute zero. B) of nuclear forces. C) of gravitational forces. D) of electrical forces. E) none of the above

Q: Which is the smallest particle? A) molecule B) atom C) proton D) neutron E) quark

Q: An element is distinct because of its number of A) protons. B) neutrons. C) electrons. D) the total mass of all the particles. E) none of the above