8^th Grade Physical Science

Structure of Matter ~ 3 a-f 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

Answer Key

1. b

2. c

3. d

4. d

5. c

6. b

7. a

8. b

9. c

10. d