Mrs. Lee 8Th Grade Physical Sciencepage 1
Mrs. Lee – 8th Grade Physical SciencePage 1
Chapter 8 Practice Test – Answer Key
______b1) A chemical bond is ______.
a)a way of organizing elements in the periodic table
b)the force that holds two atoms together
c)how elements react with each other
d)a result of combustion
______a2) The ways in which an atom can bond with other atoms depends on the atom’s ______.
a) valence electronsb) nucleusc) atomic numberd) atomic mass
______c3) The most loosely held electrons in an atom are ______.
a) unstable electronsb) covalent electrons
c) valence electronsd) low-energy electrons
______d4) The maximum number of bonds a carbon atom can form is ______.
a) oneb) twoc) threed) four
______c5) Many organic compounds ______.
a) have high melting pointsb) have high boiling points
c) do not dissolve well in waterd) conduct electricity
______a6) The monomers of complex carbohydrates are ______.
a) simple sugarsb) amino acidsc) fatty acidsd) glycerol
______b7) Pure carbon exists as all the following forms EXCEPT ______.
a) graphiteb) methanec) fullerened) diamond
______d8) Carbohydrates are made up of carbon, hydrogen, and ______.
a) sulfurb) nitrogenc) phosphorusd) oxygen
______a9) The names of saturated hydrocarbons end in ______.
a) –aneb) –inec) –ened) –yne
______c10) Substituted hydrocarbons include all of the following EXCEPT ______.
a) alcoholsb) halogen-containing compounds
c) mineralsd) organic acids
______a11) Which of the following is a natural composite?
a) woodb) fiberglassc) cellulosed) nylon
______c12) The main classes of organic compounds in living things include all of the following EXCEPT ______.
a) carbohydratesb) proteinsc) alcoholsd) lipids
______a13) Carbon atoms can form straight chains, branched chains, and rings.
a) Trueb) False
______b(esters)14) Many fullerenes have pleasant, fruity smells.
a) Trueb) False
______a15) Along with carbohydrates, lipids, and proteins, vitamins and minerals are other nutrients that contribute to a healthy diet.
a) Trueb) False
______b(hydroxyl group)16) A combination of an oxygen atom and a hydrogen atom, -OH, is called a hydrocarbon.
a) Trueb) False
______b(Proteins)17) Nucleotides are polymers made of amino acids.
a) Trueb) False
______b(saturated)18) A hydrocarbon with only single bonds in its carbon chain is called an unsaturated hydrocarbon.
a) Trueb) False
______a19) Fats and oils are energy-rich organic compounds called lipids.
a) Trueb) False
______a20) A composite is a material that combines the useful properties of two or more substances.
a) Trueb) False
______b (nucleic acids)21) DNA and RNA are examples of cholesterol.
a) Trueb) False
______a22) A pure form of carbon that forms a very hard crystal is ______.
a) diamondb) graphitec) fullerene
______a23) All hydrocarbons
a) burn easilyb) have carboxyl groupsc) have fruity smells
______c24) In a substituted hydrocarbon, an atom of another element replaces a(n) ______.
a) carbon atomb) oxygen atomc) hydrogen atom
______c25) Proteins are polymers formed from monomers called ______.
a) estersb) carbohydratesc) amino acids
______b26) Synthetic polymers that can be molded or shaped are ______.
a) celluloseb) plasticsc) isomers
______c27) Carbohydrates give your body ______.
a)the building blocks to repair body parts
b)helper molecules for chemical reactions in your body
c)energy
______a28) The building blocks of proteins are ______.
a) amino acidsb) nucleic acidsc) fatty acids
______c29) Which food is a source of fat?
a) potatoesb) ricec) butter
______b(nanotube)30) A form of pure carbon in which carbon atoms are arranged in the shape of a long, hollow tube is a fullerene.
a) Trueb) False
______a31) Compounds with the same chemical formula but different structural formulas are called isomers.
a) Trueb) False
______b(composite)32) Two or more substances combined in a new material with different properties is a DNA.
a) Trueb) False
______b(glucose)33) Starch is a complex carbohydrate made up of molecules of fatty acids.
a) Trueb) False
______b34) Carbon atoms cannot form chemical bonds with other carbon atoms.
a) Trueb) False
______a35) Hydrocarbons are organic compounds that contain only the elements hydrogen and carbon.
a) Trueb) False
______a36) Polymers are very large molecules made of monomers.
a) Trueb) False
______b37) Carbohydrates release much more energy in your body than do lipids.
a) Trueb) False
______a38) The order of nucleotides in a DNA molecule determines the differences among living things.
a) Trueb) False
Use the diagrams below to answer the following 3 questions:
______b39) Interpreting Diagrams: Which is a branched hydrocarbon chain?
a) compound A b) compound B c) neither compound is a branched chain
______b40) Applying Concepts: What kind of formula is used above to show the compounds?
a) chemical formulab) structural formulac) chemical equation
______a41) Applying Concepts: Which formula correctly describes both compounds above?
a) C4H10b) C3H7c) CH4
Use the diagrams below to answer the following 2 questions:
______a42) Classifying: What kind of substituted hydrocarbon is compound A?
a) alcoholb) organic acidc) halogen-containing compound
______c43) Applying Concepts: Which is the correct formula for compound B?
a) C4Hb) CH3Clc) CCl4
Ch 8 Practice Test – Answer Key1