Matter and Chemical Reactions Quiz

Matter and its Classification

• Matter is anything that occupies space and has mass.
• Matter can be classified as pure substances (elements and compounds) or mixtures (homogeneous or heterogeneous).
• Pure substances: consist of only one type of particle.
• Elements: consist of only one type of atom.
• Compounds: consist of more than one type of atom.
• Mixtures: consist of more than one type of particle.
• Homogenous mixtures: particles are evenly distributed.
• Heterogenous mixtures: particles are not evenly distributed.
• Suspensions: particles settle slowly after mixing.
• Colloids: particles do not settle in a mixture.
• Emulsions: substances that suspend particles for a longer time.

Chemical Reactions and Changes

• Chemical changes involve the formation of new substances with different properties than the original materials.
• Physical changes do not involve the formation of new substances; the substance’s form or state changes, but its chemical composition stays the same.
• Chemical changes are not reversible.
• Physical changes can be reversed.
• Indicators of a chemical change:
  • Heat is produced or absorbed.
  • No more of the original material remains.
  • Change in color.
  • New properties are formed.
  • Gas bubbles form in a liquid.
  • A precipitate forms in a liquid.
  • Difficult to reverse the change.
  • Hard to explain how to reverse the change.

Properties of Substances and Hazards

• Substances can have hazardous properties that pose risks to the environment or human health.
• Gas cylinders under pressure can explode.
• Flammable substances can ignite and burn (flame).
  • Oxygen can intensify a fire (flame over a circle).
• Exploding bombs release energy, fire, explosions and toxicants.
• Environmental hazards may damage the environment (e.g., aquatic environments).
• Corrosion: substances can destroy metals and human tissues
• High danger substances that can lead to immediate injury or death (corrosion skull and crossbones)
• Health hazards: substances can cause longer-term health effects.
• Hazardous substances that can cause minor health effects and ozone damage (exclamation mark symbol).
• Biohazard materials contain harmful microorganisms or toxins.
• Caustic materials: can cause chemical burns, corrode, or destroy organic tissues.

Test your understanding of matter and its classification along with chemical reactions and changes. This quiz covers pure substances, mixtures, and the distinctions between physical and chemical changes. Perfect for students looking to reinforce their knowledge in chemistry.