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Choice questions

READ QUESTION, ANSWER IT and VERIFY IT by CLICKING 'ANS' BUTTON with question number.

      






Q.1: A weather balloon with a 2-meter diameter at ambient temperature holds 525 grams of helium. What type of electronic probe could be used to determine the pressure inside the balloon?
A:(barometric)
B:(thermometric)
C: (calorimetric)
D: (spectrophotometric)
Select the labelled statement that best fits your answer.

Q.2: Which would be most appropriate for collecting data during a neutralization reaction?
A: a pH probe
B: a statistics program
C: a thermometer
D: a graphing program
Select the labelled statement that best fits your answer.

Q.3: A scientist observed changes in the gas pressure of one mole of a gas in a sealed chamber with a fixed volume. To identify the source of the changes, the scientist should check for variations in the
A: air pressure outside the chamber.
B: molecular formula of the gas.
C: temperature of the chamber.
D: isotopes of the gas.
Select the labelled statement that best fits your answer.

Q.4: Electrical fires cannot be safely put out by dousing them with water. However, fire extinguishers that spray solid carbon dioxide on the fire work very effectively. This method works because carbon dioxide
A: displaces the oxygen.
B: renders the fire’s fuel non-flammable.
C: forms water vapor.
D: blows the fire out with strong wind currents.
Select the labelled statement that best fits your answer.

Q.5: In order to advance to the level of a theory, a hypothesis should be
A: obviously accepted by most people.
B: a fully functional experiment.
C: in alignment with past theories.
D: repeatedly confirmed by experimentation.
Select the labelled statement that best fits your answer.

Q.6: Matter is made of atoms that have positive centers of neutrons and protons surrounded by a cloud of negatively charged electrons. This statement is
A: a theory.
B: a hypothesis.
C: an inference.
D: an observation.
Select the labelled statement that best fits your answer.

Q.7: When a metal is heated in a flame, the flame has a distinctive color. This information was eventually extended to the study of stars because
A: the color spectra of stars indicate which elements are present.
B: a red shift in star color indicates stars are moving away.
C: star color indicates absolute distance.
D: it allows the observer to determine the size of stars.
Select the labelled statement that best fits your answer.

Q.8: Why is cobalt (Co) placed before nickel (Ni) on the periodic table of the elements even though it has a higher average atomic mass than nickel?
A: Nickel has one more proton.
B: Cobalt was discovered first.
C: Nickel has fewer electrons.
D: Cobalt has a lower density
Select the labelled statement that best fits your answer.

Q.9: Generally, how do atomic masses vary throughout the periodic table of the elements?
A: They increase from left to right and top to bottom.
B: They increase from left to right and bottom to top.
C: They increase from right to left and top to bottom.
D: They increase from right to left and bottom to top.
Select the labelled statement that best fits your answer.

Q.10: Iodine would have chemical properties most like
A: calcium (Ca).
B: silicon(Si).
C: chlorine (Cl).
D: xenon (Xe).
Select the labelled statement that best fits your answer.

Q.11: Which of the following atoms has six valence electrons?
A: magnesium(Mg)
B: silicon(Si)
C : sulfur(S)
D: argon (Ar).
Select the labelled statement that best fits your answer.

Q.12: Which statement best describes the density of an(atom)'s nucleus?
A: The nucleus occupies most of the atom’s volume but contains little of its mass.
B: The nucleus occupies very little of the atom’s volume and contains little of its mass.
C: The nucleus occupies most of the atom’s volume and contains most of its mass.
D: The nucleus occupies very little of the atom’s volume but contains most of its mass
Select the labelled statement that best fits your answer.

Q.13: Firing of alpha particles at the gold leaf resulted in more than 98% absorption, less than 2% deflection at large angles and almost no bounce back.
What information do the experimental results above reveal about the nucleus of the gold atom?
A: The nucleus contains less than half the mass of the atom.
B: The nucleus is small and is the densest part of the atom.
C: The nucleus contains small positive and negative particles.
D: The nucleus is large and occupies most of the atom’s space
Select the labelled statement that best fits your answer.

Q.14: Why are enormous amounts of energy required to separate a nucleus into its component protons and neutrons even though the protons in the nucleus repel each other?
A: The force of the protons repelling each other is small compared to the attraction of the neutrons to each other.
B: The electrostatic forces acting between other atoms lowers the force of repulsion of the protons.
C: The interactions between neutrons and electrons neutralize the repulsive forces between the protons.
D: The forces holding the nucleus together are much stronger than the repulsion between the protons.
Select the labelled statement that best fits your answer.

Q.15: A 2-cm-thick piece of cardboard placed over a radiation source would be most effective in protecting against which type of radiation?
A: alpha
B: beta
C: gamma
D: x-ray
Select the labelled statement that best fits your answer.

Q.16: Which of the following is a monatomic gas at STP?
A: chlorine
B: fluorine
C: helium
D: nitrogen.
Select the labelled statement that best fits your answer.

Q.17: When cations and anions join, they form what kind of chemical bond?
A: ionic
B: hydrogen
C: metallic
D: covalent.
Select the labelled statement that best fits your answer.

Q.18: Some of the molecules found in the human body are NH2CH2COOH (glycine), C6H12O6 (glucose), and CH3(CH2)16COOH (stearic acid). The bonds they form are
A: nuclear.
B: metallic.
C: ionic.
D: covalent.
Select the labelled statement that best fits your answer.

Q.19: What type of bond do the molecules of Chlorine(Cl2), ammonia (NH3) and methane (CH4) have in common?
A: covalent
B: ionic
C: metallic
D: polar.
Select the labelled statement that best fits your answer.

Q.20: The reason salt crystals, such as KCl, hold together so well is because the cations are strongly attracted to
A: neighboring cations.
B: the protons in the neighboring nucleus.
C: free electrons in the crystals.
D: neighboring anions.
Select the labelled statement that best fits your answer.

Q.21: Which substance is made up of many monomers joined together in long chains?
A: salt
B: protein
C: ethanol
D: propane
Select the labelled statement that best fits your answer.

Q.22: Which element is capable of forming stable, extended chains of atoms through single, double, or triple bonds with itself?
A: carbon
B: oxygen
C: nitrogen
D: hydrogen
Select the labelled statement that best fits your answer.

Q.23: Proteins are large macromolecules composed of thousands of subunits. The structure of the protein depends on the sequence of
A: lipids.
B: monosaccharides.
C: amino acids.
D: nucleosides
Select the labelled statement that best fits your answer.

Q.24: When someone standing at one end of a large room opens a bottle of vinegar, it may take several minutes for a person at the other end to smell it. Gas molecules at room temperature move at very high velocities, so what is responsible for the delay in detection of the vinegar?
A: the increase in the airspace occupied by vinegar molecules
B: the chemical reaction with nerves, which is slower than other sensory processes
C: attractive forces between the air and vinegar molecules
D: random collisions between the air and vinegar molecules.
Select the labelled statement that best fits your answer.

Q.25: Methane (CH4) gas diffuses through air because the molecules are
A: moving randomly.
B: dissolving quickly.
C: traveling slowly.
D: expanding steadily
Select the labelled statement that best fits your answer.

Q.26: The volume of 400 mL of chlorine gas at 400 mm Hg is decreased to 200 mL at constant temperature. What is the new gas pressure?
A: 400 mm Hg
B: 300 mm Hg
C: 800 mm Hg
D: 650 mm Hg
Select the labelled statement that best fits your answer.

Q.27: Under what circumstance might a gas decrease in volume when heated?
A: The gas is held constant at STP.
B: The gas remains under uniform temperature.
C: The gas is placed under increasing pressure.
D: The gas undergoes a decrease in pressure
Select the labelled statement that best fits your answer.

Q.28 Standard temperature and pressure (STP) are defined as
A: 0 ºC and 1.0 atm pressure.
B: 0 ºC and 273 mm Hg pressure.
C: 0 K and 1.0 atm pressure.
D: 0 K and 760 mm Hg pressure
Select the labelled statement that best fits your answer.

Q.29 Under which of the following sets of conditions will a 0.50 mole sample of helium occupy a volume of 11.2 liters?
A: 298 K and 0.90 atm
B: 273 K and 1.10 atm
C: 373 K and 0.50 atm
D: 273 K and 1.00 atm
Select the labelled statement that best fits your answer.

Q.30 What is the equivalent of 423 kelvin in degrees Celsius?
A: –223 ºC
B: –23 ºC
C: 150 ºC
D: 696 ºC
Select the labelled statement that best fits your answer.






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