Download PHYS 1400 Sample Exam Questions: Properties of Matter (Atoms) 1

PHYS 1400 Sample Exam Questions: Properties of Matter (Atoms)
1.
Aristotle believed
C) that the universe could be understood. He was the first person to develop a philosophy
based on the idea that only through observation and testing could the natural world be
described and comprehended.
2.
What is the difference between an experiment and an observation?
B) Observing is recording what you see (or hear, whatever) without interfering (look, but don't
touch). Experimentation is intentionally acting on or manipulating something to see what
happens.
3.
The steps of the scientific method
A) are flexible; when science gets done in the real world, the steps may not be followed in
order.
4.
What separates science from something like art or literature?
C) Scientific ideas must be tested before they can be accepted, and if any test proves the idea
wrong, the idea must be changed. Not so with art or music. You may not like to look at
Picasso or listen to Bach, but that does not make the paintings or the music wrong.
5.
How does an hypothesis differ from a theory?
C) An hypothesis is an educated guess. It can become a theory after is has been welltested and
is not shown to be false.
6.
How does a scientist choose between competing hypotheses?
C) He may not really have to choose; as more experiments or observations are performed,
some of the competing hypotheses may be eliminated as they are shown to be false.
7.
Why do scientists use equations?
D) Equations are a concise and convenient way to express ideas, and can be used to make
precise predictions.
8.
Which of the following is an example of genuine science (as opposed to pseudoscience)?
A) Astronomy.
9.
Why does Mendeleyev generally receive the credit for developing the periodic table of the elements,
even though Lothar Meyer came up with almost exactly the same table at almost exactly the same
time?
D) Mendeleyev used his periodic table to predict the existence of previously undiscovered
elements. For example, the element gallium was discovered after Mendeleyev's table
indicated that an element should exist with its specific properties.
10. What is energy?
A) Energy is the ability to do work. Whatever work is.
11. When Democritus proposed the atomic theory of matter more than 2000 years ago, he suggested that
A) atoms were particles of matter too small to be seen. These atoms could not be split into
smaller pieces.
12. The atomic theory of matter
D) is over 2000 years old; Democritus proposed the existence of atoms in about 400 BC.
13. Dalton’s weight ratios, Brownian motion, and Einstein’s rates of diffusion
C) are indirect evidence that is consistent with atomic theory.
14. The electron was discovered
C) in 1897 by J.J. Thomson, who determined that cathode ray particles were too small to be
ions.
15. The atomic nucleus was discovered
A) in 1911 by Ernest Rutherford, who bombarded a gold foil with particles to observe their
path.
16. How do we know that atoms really exist?
C) There is indirect evidence: Brownian motion. If that's not enough for you, there is also direct
evidence: using an electron microscope, you can obtain the actual image of an atom.
17. How do we know that atoms are motion?
B) Diffusion: you can watch an ink drop spread through a glass of water, or smell the cookies
baking.
18. How did Einstein contribute to our understanding of atoms?
D) He calculated rates of diffusion, which could be measured experimentally.
19. What's so important about Max vonLaue and his shooting a beam of xrays at a piece of metallic foil?
D) Not only did it show that atoms really exist, it also revealed that long—range order was
possible, and that different metals could have different crystal structures.
20. Which of the following is not true about atoms?
D) If you added up the number of atoms in the universe, there would be about 117.
21. Protons
A) have a positive charge.
22. Neutrons
C) are found in the nucleus of atoms.
23. Electrons
B) have an extremely small mass, compared to protons or neutrons.
24. Beryllium has an atomic number of 4. This means
C) there are 4 protons in the nucleus.
25. Sodium has an atomic number of 11, and an atomic weight of 22.99. Why isn’t the weight exactly 22?
B) There will be 11 protons, but some isotopes of sodium may have more than 11 neutrons,
which increases the average weight.
26. Explain the difference between an atom and a molecule.
D) A molecule consists of two or more atoms chemically bonded together. The atoms may be
the same kind, or they may be different types.
27. Most of the oxygen in the earth's atmosphere is in the form of
B) diatomic molecules. One oxygen atom easily combines with a second to form a molecule.
28. The most abundant element in the universe is
A) hydrogen.
29. How is a mixture different from compound?
B) The components of a mixture can be combined or separated mechanically, like by sifting.
30. An element is
B) composed entirely of like atoms, having a single type of atomic structure.
31. The principle of conservation of mass states that
D) however much mass exists in the universe now, that's how much there has always been.
Matter cannot be created or destroyed.
32. How did Antoine Lavoisier demonstrate the conservation of mass?
C) He burned a scrap of paper in a closed container. By weighing the container before, and
again after, he was able to show that even though the paper was gone, there was still the
same amount of matter in the box.
33. What exactly is Avogadro's Principle?
B) Not everything is made of the same number of atoms, but if you isolate equal volumes of
different gases, and they are at the same temperature, then they will have the same number
of molecules.
34. Atomic mass unit?
B) A hydrogen atom weighs exactly 1amu, which is essentially the mass of a proton.
35. The periodic table
A) organizes the elements in both rows and columns that share similar properties.
36. Find the element Indium (In) on the attached periodic table. What is the atomic number of In?
B) 49. There are exactly 49 protons in its nucleus.
37. What is the atomic weight of In?
C) 114.8. Each proton and neutron in the nucleus weighs 1amu. The weight has a decimal
because some isotopes exist with more or fewer neutrons, so this number is an average
value.
38. Find the element titanium (Ti.) on the attached periodic table. What is the atomic number of Ti?
A) 22. It has exactly 22 protons in its nucleus.
39. What is the atomic weight of Ti?
C) 47.87. Each proton and neutron in the nucleus weighs exactly 1amu. The weight has a
decimal because some isotopes exist with more or fewer neutrons, so this number is an
average value.
40. Which element comes the closest to having twice the atomic weight of Ti?
A) Zirconium (Zr).
B) Molybdenum (Mo).
C) Ruthenium (Ru).
D) Technetium (Tc).
41. When a hydrogen nucleus is fused with a lithium nucleus, the result is
C) a beryllium nucleus.
42. What is antimatter?
B) Antimatter particles have the same mass, but opposite charge as particles of matter.
43. What are quarks?
D) Quarks are the subatomic particles that make up protons and neutrons.
44. And what about dark matter?
C) It’s matter that hasn’t been observed, but is predicted to exist by the effect it has on stars
and galaxies. There seems to be an awful lot of it in the universe.