DO NOT WRITE ON THIS TEST
Mrs. Lee – 8th Grade Physical Science
Page 1
Chapter 5 Practice Test – Answer Key
______ b
1) A(n) ______ is an atom or group of atoms that has an electric charge.
a) compound
b) ion
c) crystal
d) neutron
______ c
2) A covalent bond is called ______ if the atoms equally share one or more pairs of
electrons.
a) double
b) ionic
c) nonpolar d) polar
______ b
3) An attraction between a positive metal ion and the electrons surrounding it is a
______.
a) covalent bond
b) metallic bond
c) nonpolar bond
d) triple bond
______ d
4) Which of the following does NOT apply to valence electrons?
a) loosely held by the nucleus
b) shown on electron dot diagrams
c) transferred or shared in bonding d) make up most of the atom’s mass
______ b
5) The number of ______ remains the same from top to bottom in a group in the
periodic table.
a) protons
b) valence electrons c) electrons d) neutrons
______ c
6) Elements in Group 17, the halogen family, are very reactive because their atoms
have ______ valence electrons.
a) zero
b) one
c) seven
d) eight
______ b
7) A molecule in which the polar covalent bonds do not cancel out will be ______.
a) nonpolar
b) polar
c) ionic
d) metallic
______ a
8) Which of the following is NOT a characteristic that results from metallic bonding?
a) hard, brittle crystals
b) electrical conductivity
c) ability to be hammered into sheets
d) luster
______ d
9) ______ ions are composed of more than one atom.
a) Covalent b) Molecular c) Polar
d) Polyatomic
______ b
10) In a double bond, ______ electrons are shared.
a) two
b) four
c) six
d) eight
______ a
11) An alloy is a mixture made of 2 or more elements that has the properties of a metal.
a) True
b) False
______ a
12) Most atoms become less reactive after a change to a total number of eight valence
electrons.
a) True
b) False
Ch 5 Practice Test Answer Key
1
DO NOT WRITE ON THIS TEST
Mrs. Lee – 8th Grade Physical Science
Page 2
Chapter 5 Practice Test – Answer Key
______ b (molecule) 13) A neutral group of atoms joined by covalent bonds is called a subscript.
a) True
b) False
______ b (positive) 14) A negative ion is formed when an atom loses an electron.
a) True
b) False
______ b (six) 15) In a reaction, atoms with five valence electrons will probably gain 2 electrons or
share 2 covalent bonds.
a) True
b) False
______ a
16) Freely moving valence electrons account for electrical conductivity in metals.
a) True
b) False
______ b (inert gases)
17) The most stable elements in the periodic table are found in the family
of alkali metals.
a) True
b) False
______ b (neutral) 18) Ions form electrically negative compounds.
a) True
b) False
______ b (polar)
19) Atoms in a nonpolar covalent bond carry slight electrical charges.
a) True
b) False
______ a
20) A group of elements shares the same number of valence electrons.
a) True
b) False
______ c
21) The electrons of an atom that are at the highest energy level are called ______.
a) positive electrons b) ionic electrons
c) valence electrons
______ b
22) Which includes the symbol for an element surrounded by dots?
a) chemical formula b) electron dot diagram
c) molecular compound
______ c
23) A period of the periodic table ends when the highest energy level of an element’s
atoms has ______.
a) four electrons
b) six electrons
c) eight electrons
______ a
24) The noble gases have eight valence electrons and, as a result, are ______.
a) stable
b) very reactive
c) shiny
______ b
25) An atom with an electric charge is called a(n) ______.
a) compound
b) ion
c) neutron
Ch 5 Practice Test Answer Key
2
DO NOT WRITE ON THIS TEST
Mrs. Lee – 8th Grade Physical Science
Page 3
Chapter 5 Practice Test – Answer Key
______ c
26) MgCl2 is an example of a(n) ______.
a) electron dot diagram
b) element
c) chemical formula
______ b
27) A neutral group of atoms joined by covalent bonds is a(n) ______.
a) ion
b) molecule
c) element
______ b
28) A covalent bond in which the atoms equally share a pair of electrons is called
______.
a) polar
b) nonpolar
c) ionic
______ c
29) An attraction between a positive metal ion and the valence electrons surrounding it
is a(n) ______.
a) ionic bond
b) covalent bond
c) metallic bond
______ a
30) Metals are easy to bend because ______.
a) metal ions can be pushed out of position
b) metals form covalent bonds
c) metals are brittle
______ a
31) The force of attraction that holds 2 atoms together is called a chemical bond.
a) True
b) False
______ b
32) Most atoms are less likely to react with other atoms when they have 4 valence
electrons.
a) True
b) False
______ a
33) When an atom loses an electron, a positive ion forms.
a) True
b) False
______ a
34) When 2 atoms share 2 pairs of electrons, a double bond forms.
a) True
b) False
______ b (alloy)
35) A mixture made of 2 or more elements that has the properties of metal is a
crystal.
a) True
b) False
______ a
36) Neutrons are particles in the nucleus of an atom that have no electric charge.
a) True
b) False
______ b
37) The most stable elements in the periodic table are the halogens.
a) True
b) False
Ch 5 Practice Test Answer Key
3
DO NOT WRITE ON THIS TEST
Mrs. Lee – 8th Grade Physical Science
Page 4
Chapter 5 Practice Test – Answer Key
______ a
38) Atoms in polar covalent bonds carry slight electric charges.
a) True
b) False
______ b
39) Metals are poor conductors of heat.
a) True
b) False
The diagram below is an electron dot diagram. Use the diagram to answer the following 2
questions:
______ b
40) Interpreting Diagrams: How many valence electrons does an atom of chlorine
have?
a) 1
b) 7
c) 8
______ a
41) Predicting: How many more electrons are needed to make a chlorine atom stable?
a) 1
2) 7
3) 8
Four electron dot diagrams are shown below. Use the diagrams to answer the following 3
questions:
______ b
42) Interpreting Diagrams: What kind of bonds do these compounds have?
a) ionic bonds
b) covalent bonds
c) metallic bonds
______ a
43) Applying Concepts: Which compound has a polar bond?
a) HF
b) F2
c) O2
______ c
44) Applying Concepts: Which compound has a triple bond?
a) O2
b) F2
c) N2
Ch 5 Practice Test Answer Key
4
DO NOT WRITE ON THIS TEST
Mrs. Lee – 8th Grade Physical Science
Page 5
Chapter 5 Practice Test – Answer Key
______ b
45) The atom is made of protons, electrons, and ______.
a) valence electrons b) neutrons c) molecules d) ions
______ d
46) Reactant atoms and molecules interact to form products with ______.
a) identical physical properties
b) different physical properties
c) identical chemical properties
d) different chemical properties
______ c
47) In chemical reactions, the number of atoms ______.
a) varies according to the elements involved
b) changes from one reactant to another
c) stays the same
d) depends on atom arrangement
______ a
48) Compounds are formed by ______.
a) combining 2 or more different elements
b) bombarding atoms with high-speed particles
c) combining 2 or more different nuclei
d) dissolving a solid in a liquid
______ a
49) Valence electrons in an atom are those that are ______.
a) held most loosely
b) of the lowest energy level
c) always easily lost
d) never easily lost
______ c
50) An electron dot diagram shows an atom’s number of ______.
a) protons
b) electrons c) valence electrons d) chemical bonds
______ a
51) When an atom loses or gains electrons, it becomes a(n) ______.
a) ion
b) formula
c) crystal
d) subscript
______ c
52) A covalent bond in which electrons are shared unequally is a ______.
a) double bond
b) triple bond
c) polar bond
d) nonpolar bond
______ d
53) The metal atoms in stainless steel are held together by ______.
a) ionic bonds
b) polar bonds
c) covalent bonds
d) metallic bonds
Ch 5 Practice Test Answer Key
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