Unit 5 (Reactions) Test

Numbers that precede symbols and formulas in a chemical equation are called? 

• Catalysts

• Superscripts

• Subscript

• Coefficients

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

• Oxidation Number

• Atomic Number 

• Ionic Number

• Atomic Mass

In a chemical change, energy can be? 

• Neither created nor destroyed

• Either created or destroyed 

• Destroyed, but not created

• Created, but not destroyed

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 Symbol

• Superscript

• Subscript

• Chemical Formula

Both a fusion reaction and a fission reaction ______. 

• Take place at room temperature

• Produce energy

• Use hydrogen as a fuel

• Cause chain reactions

Radioactive tracers are useful in? 

• Determining medical problems

• Calculating the ages of fossils 

• Fueling nuclear reactions

• Treating brain tumors

Which element comes first in a chemical formula? 

• Those with positive oxidation numbers. 

• The first element is always a nonmetal.

• Those with negative oxidation numbers.

• The first element is always a metal.

The stability of a nucleus depends on the _________. 

• Atomic Number

• Number of Neutrons 

• Atomic Mass

• Proton-neutron Ratio

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

• Magnetic

• Polyatomic

• Ionic

• Covalent

The most penetrating form of nuclear radiation is _____ radiation.  

• Alpha

• Gamma

• Beta

• Delta