Focus On Physical Science: California Grade 8

Chapter 5: Combining Atoms and Molecules

Standard Assessment

1.
(n) __________ is a pure substance that contains two or more elements. 3.b
A)ion
B)compound
C)molecule
D)solution
2.
______ are solids in which atoms are arranged in a regular pattern called a unit cell. 3.c
A)Monomers
B)Polymers
C)Crystals
D)Metals
3.
A double bond is one in which __________. 3.b
A)an atom loses two pairs of electrons to another atom
B)two atoms are joined by sharing electrons
C)three pairs of electrons are shared
D)atoms share two pairs of electrons
4.
A(n) ________ is a combination of chemical symbols indicating what elements are present in a molecule. 3.b
A)superscript
B)chemical equation
C)subscript
D)chemical formula
5.
A(n) __________ is a force that holds two atoms together. 3.b
A)chemical compound
B)isotope
C)chemical bond
D)ion
6.
A(n) __________ is a method of representing atoms and the electrons in their outer energy levels. 3.a
A)chemical symbol
B)electron dot diagram
C)chemical formula
D)chemical equation
7.
A(n) __________ is an atom that has gained or lost an electron and is no longer neutral. 3.a
A)ion
B)compound
C)molecule
D)isotope
8.
A(n) __________ is formed between atoms when they share electrons. 3.b
A)ionic bond
B)covalent bond
C)salt
D)electrical bond
9.
An ionic salt is made up of __________ and __________ lined up in a regular pattern. 3.b
A)positive metal ion, noble gases
B)negative metal ions, positive nonmetal ion
C)positive metal ions, negative nonmetal ions
D)negative metal ions, positive metalloid ions
10.
Based on what you know about sodium chloride, which of the following elements would you expect to form an ionic salt? 3.f
A)potassium and nitrogen
B)sodium and carbon
C)sodium and phosphorus
D)potassium and iodine
11.
Because metals form _______ they are good conductors. 3.c
A)covalent bonds
B)ionic bonds
C)metallic bonds
D)polar
12.
Crystalline solids have __________. 3.c
A)an amorphous shape
B)no phase changes
C)repeating three dimensional patterns
D)two-dimensional crystalline patterns
13.
DNA consists of repeating units linked in a chain, so it is a ________. 3.c
A)monomer
B)polymer
C)crystal
D)covalent bond
14.
In the formula H2O, what does the number 2 indicate? 3.b
A)Each hydrogen atom gains two electrons from the oxygen atom.
B)Each hydrogen atom loses two electrons to the oxygen atom.
C)There are two atoms of hydrogen in this molecule.
D)Two atoms each of hydrogen and oxygen are in this molecule.
15.
Malleability is __________. 7.c
A)the hardness of an object
B)the ability to be drawn out into a wire
C)the shininess of an object
D)the ability to be hammered, pressed, or rolled into thin sheets
16.
The ions in ionic compounds are held together by __________. 3.b
A)ionic bonds
B)covalent bonds
C)equal sharing of electrons
D)unequal sharing of electrons
17.
What is a property of many metals? 7.c
A)shiny appearance
B)liquid at room temperature
C)dull appearance
D)soft
18.
What substance does not have the property of ductility? 7.c
A)copper
B)water
C)silver
D)platinum
19.
Which of the following elements would make the best electrical wire? 7.c
A)fluorine
B)carbon
C)copper
D)selenium
20.
Which of the following is a characteristic of most metals? 7.c
A)gases at room temperature
B)dull in appearance
C)poor conductors of electricity
D)shiny luster
Grade 8
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