Download CHEMISTRY BENCHMARK #1 DO NOT WRITE ON THIS EXAM

CHEMISTRY BENCHMARK #1
DO NOT WRITE ON THIS EXAM.
WRITE ONLY ON THE ANSWER SHEET.
You are not permitted to use a calculator on the Science Test.
1. (1.a) Which of the following ordered pairs of elements shows an increase in atomic number
but a decrease in average atomic mass?
a. Ag to Pd
b. Co to Ni
c. Cr to Mo
d. Ge to Sn
2. (1.a) 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. Cobalt has a lower density.
b. Cobalt was discovered first.
c. Nickel has one more proton.
d. Nickel has fewer electrons.
3. (1.a) Generally, how do atomic masses vary throughout the periodic table of the elements?
a. They increase from left to right and bottom to top.
b. They increase from right to left and top to bottom.
c. They increase from right to left and bottom to top.
d. They increase from left to right and top to bottom.
4. (1.a) 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. it allows the observer to determine the size of stars.
b. The color spectra of stars indicate which elements are present.
c. Star color indicates absolute distance.
d. A red shift in star color indicates stars are moving away.
5. ( 1.b) Iodine would have chemical properties most like
a. xenon (Xe).
b. tellurium (Te).
c. chlorine (Cl).
d. manganese (Mn).
6. (1.b) Which of the following elements is classified as a metal?
a. bromine
b. lithium
c. helium
d. Sulfur
7. ( 1.b) Which of the following elements is a metalloid?
a.
b.
c.
d.
Iron(#26)
Iodine(#53)
Sulfur(#16)
Germanium(#32)
8. ( 1.b)Which of the following elements is a halogen?
a.
b.
c.
d.
Sulfur(#16)
Iron(#26)
Germanium(#32)
Iodine(#53)
9. ( 1.b)Metalloids are elements that show:
a. only properties of nonmetals
b. properties of the Noble Gases
c. both metallic and nonmetallic properties
d. only properties of metals
10. ( 1.c) Which of the following atoms has the largest atomic radius?
a. chlorine (Cl)
b. iodine (I)
c.
d.
magnesium (Mg)
barium (Ba)
11. ( 1.c) The most reactive metals on the periodic table belong to the:
a. Transition metals
b. Noble gases
c. Alkali metals group
d. Rare earth metals
12. ( 1.c) Given the representation of a chlorine atom, which circle might represent a chloride
anion, Cl1-?
a. Circle D
b. Circle B
c. Circle C
d. None of these
13. (1.c) Which statement about the alkali metals is correct?
a. They are located in the left-most column of
the periodic table.
b. They are extremely nonreactive.
c. They are usually gases.
d. They form negative ions with a 1- charge.
14. ( 1.d) Valence electrons determine an atom´s
a. mass.
b. chemical properties.
c. electric charge.
d. period.
15. ( 1.d) Give the correct number valence electrons for the elements Krypton, Kr,#36
a. 5
b. 6
c. 7
d. 8
16. ( 1.d) Give the correct number of valence electrons for the element nitrogen, N, atomic #7.
a. 5
b. 6
c. 7
d. 8
17. ( 1.e) 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 but contains most 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 and contains little of its mass.
18. ( 1.e) The particle with the least mass would be the
a. proton.
b. neutron.
c. nucleus.
d. electron.
19. (2.a) Which of the following is a monatomic gas at STP?
a. chlorine
b. fluorine
c. helium
d. Nitrogen
20. ( 2.a )When cations and anions join, they form what kind of chemical bond?
a. ionic
b. metallic
c. hydrogen
d. Covalent
21. ( 2.a) A molecule with covalent bonds forms when atoms
a. share electrons.
b. fuse nuclei.
c. split nuclei.
d. exchange electrons.
22.( 2.a )Bonds between atoms of metals are generally:
a.
b.
c.
Ionic
Metallic
Covalent
d. All of the above
23. ( 2.b) Which of the following correctly shows how carbon and hydrogen bond to form a
compound?
a.
b.
c.
d.
24. ( 2.b) 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. covalent
c. metallic
d. ionic
25. ( 2.b) What type of bond do all of the molecules in the table above have in common?
a. covalent
b. metallic
c. ionic
d. polar
26. (2.c) The reason salt crystals, such as NaCl, hold together so well is because the cations are
strongly attracted to
a. free electrons in the crystals.
b. neighboring anions.
c.
d.
the protons in the neighboring nucleus.
neighboring cations.
27. (2.d) The random molecular motion of a substance is greatest when the substance is
a.
b.
c.
d.
a liquid.
a gas.
condensed.
frozen.
28. (2.e) Which of the following electron dot notations is correct for the element carbon, C,
atomic #6?
a. I
b. II
c. III
d. IV
29. ( 2.e) Which of the following electron dot notations is correct for the element phosphorus, P,
atomic #15?
a. I
b. II
C. III
d. IV
30. (2.e) How is the Lewis dot structure of PF₃ different than the Lewis dot structure for BF₃?
A. There is a lone pair on the central atom in PF₃.
B. There is a lone pair on the central atom in BF₃.
C. BF₃ has more electrons around the central atom than PF₃.
D. BF₃ has more Fluorine atoms around the central atom than PF₃.
31. (11.a) 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 interactions between neutrons and electrons neutralize the repulsive forces between
the protons.
c. The electrostatic forces acting between other atoms lowers the force of repulsion of the
protons.
d. The forces holding the nucleus together are much stronger than the repulsion between
the protons.
32. (11.a) The most abundant isotope of lead contains 82 protons and 124 neutrons packed
closely together in the nucleus. Why do the protons stay together in the nucleus rather than fly
apart?
a. Electrostatic forces between neutrons and protons hold the nucleus together.
b. Nuclear forces overcome repulsive forces between protons in the nucleus.
c. Electrons in neighboring atoms neutralize repulsive forces between protons.
d. Neutrons effectively block the protons and keep them far apart to prevent repulsion.
33. ( 11. d) 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. x-ray
c. beta
d. gamma
34. ( 11. d)Which equation correctly represents the alpha decay of polonium-214?
a.
b.
c.
d.
35. (Inv. c) 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.
36. (Inv. f)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.
b.
c.
d.
a theory.
a hypothesis.
an inference.
an observation.
Short Answer:
Write your answers in complete sentences and show all your work on the space provided
on the scantron paper only to receive full credit. (3 points each)
37. ( 2.a) the chemical formula for Vitamin A, C20H30O, tell me what the elements in this
compound are, and how many atoms of each element are in a molecule of Vitamin A?
C:
H:
O:
38. ( 2.c) Describe and give an example for the followings:
a. Octet rule
b. Cation
c. Anion
39. ( 2.e) Draw the electron dot structure for the followings:
a. Cl2
b. N
c. Ca Cl2
40. ( 2. a) Complete the table below with the corresponding ionic compound
Ions
H+
Cu2+
Sn4+
Cl-