Chapter 20 8th Grade Science Putman

In a chemical formula, the number of each type of atom in the compound is shown by numbers called _______.

• superscripts

• oxidation numbers

• chemical symbols

• subscripts

The elements that make up a compound and the exact number of atoms of each element in a unit of the compound can be shown in a ____.

• chemical formula

• superscript

• chemical symbol

• subscript

A chemical bond that occurs when atoms share electrons is a(n) ____ bond.

• covalent

• polyatomic

• ionic

• magnetic

The ____ tells you how many electrons an atom must gain, lose, or share to become stable.

• atomic mass

• ionic number

• atomic number

• oxidation number

How many electrons are needed in the outer energy levels of most atoms for the atom to be chemically stable?

• 8

• 6

• 4

• 2

What kind of chemical bond is formed when an equal exchange of electrons occurs?

• ionic

• magnetic

• hydrate

• covalent

How many hydrogen atoms are present in one molecule of ammonium acetate, NH₄C₂H₃O₂?

• 2

• 4

• 6

• 8

What is the name of the compound with the formula NaCl?

• sodium chloride

• sodium dichloride

• chlorine sodiate

• sodium chlorate

Why do the noble gases NOT form compounds readily?

• They have seven electrons in the outer

  energy levels.

• They have no electrons.

• They have empty outer energy levels.

• Their outer energy levels are

  completely filled with electrons.

What is the name of a binary compound made up of lithium and chlorine?

• lithium chloride

• lithium chlorate

• chlorine lithium

• chlorine lithiate