Chemical Reactions Quiz

What is the frequency of occurrence of various elements in an equation called?

• c-number

• e-number

• f-number

• m-number

Which element should you start balancing first?

• The element that is a gas

• The element that is a non-metal

• The element with the least frequency number

• The element with the highest atomic number

If two metallic elements have the same frequency number, which should be balanced first?

• The one with the lowest atomic number

• The one that is a liquid

• The one with the highest atomic number

• The one that is a non-metal

In balancing non-metallic elements with the same frequency number, which should be balanced first?

• The one with the lowest atomic number

• The one with the highest atomic number

• The one that is a metal

• The one that is a gas

What type of reaction is defined as a combination of two or more elements or compounds to form a single compound?

• Synthesis reaction

• Combination reaction

• Thermal reaction

• Decomposition reaction

What is an example of a combination reaction?

• H₂ + O₂ → H₂O

• 2HgO → 2Hg + O₂

• PbS + O₂ → PbSO₄

• 2Mg + O₂ → 2MgO

What is a synthetic reaction?

• A reaction that involves only non-metals

• A reaction that occurs in the presence of heat

• A reaction that combines elements to form a new compound

• A reaction that breaks down compounds

What type of reaction involves breaking down a compound into elements or simple compounds?

• Thermal reaction

• Decomposition reaction

• Synthesis reaction

• Combination reaction

What is thermal decomposition?

• Decomposition by heat

• Combination of elements

• Balancing of equations

• Synthesis of compounds

What is the result of the thermal decomposition of metal oxides?

• Formation of new compounds

• Release of heat

• Formation of elements

• Combination of gases