test tmmr!

• What is always formed in a chemical reaction?

  New substances
• Why are chemical changes said to be irreversible?

  They cannot be easily reversed
• Are new substances formed in a physical change?

  No
• What are two ways to tell if a chemical reaction has occurred?

  • Color change
  • Gas emitted
• What type of change involves energy change?

  Chemical change
• What does an exothermic reaction release?

  Energy
• What type of reaction takes in energy?

  Endothermic reaction
• What happens to atoms during a chemical reaction?

  They rearrange to form new products
• What is the thermal decomposition process?

  Breaking down a large molecule into smaller ones
• What is produced when copper carbonate is heated?

  Copper oxide and carbon dioxide
• What is the scientific name for burning?

  Combustion
• What are the products of fossil fuel combustion?

  Water vapor and carbon dioxide
• What is the significance of the law of conservation of mass in chemical reactions?

  Mass is conserved; it cannot be created or destroyed
• What is the main component of fossil fuels?

  Carbon
• What happens to the energy during an endothermic reaction?

  Energy is absorbed from the surroundings
• What is the result of a displacement reaction?

  A more reactive metal displaces a less reactive one
• What is the role of catalysts in chemical reactions?

  They speed up the reaction without being consumed
• What is the process of breaking down a compound using heat called?

  Thermal decomposition
• What is the main difference between a physical change and a chemical change?

  A chemical change produces new substances
• What is the term for a reaction that releases heat?

  Exothermic reaction
• What happens to the atoms in a reactant during a chemical reaction?

  They rearrange to form products
• What is the result of a combustion reaction?

  Water and carbon dioxide
• What is the significance of the products formed in a chemical reaction?

  They determine the reaction's outcome
• What is the main product of burning hydrocarbons?

  Carbon dioxide
• What is the role of water in combustion reactions?

  It is a product of the reaction
• What is the term for the energy required to start a reaction?

  Activation energy
• What happens to the energy in an exothermic reaction?

  It is released into the surroundings
• What is the main characteristic of a displacement reaction?

  A more reactive element displaces a less reactive one
• What is the significance of the thermal decomposition of compounds?

  It breaks down compounds into simpler substances
• What is the result of a thermal decomposition reaction?

  Smaller molecules from larger ones
• What is the role of heat in chemical reactions?

  It can provide energy to initiate reactions
• What is the term for the process of breaking down a compound into its elements?

  Decomposition
• What is the significance of the products formed in a combustion reaction?

  They are typically gases like CO2 and H2O
• What is the main product of burning fossil fuels?

  Carbon dioxide
• What is the significance of the law of conservation of mass in chemical reactions?

  Mass is conserved; it cannot be created or destroyed
• What is the main component of fossil fuels?

  Carbon
• What happens to the energy during an endothermic reaction?

  Energy is absorbed from the surroundings
• What is the result of a displacement reaction?

  A more reactive metal displaces a less reactive one
• What is the role of catalysts in chemical reactions?

  They speed up the reaction without being consumed
• What is the process of breaking down a compound using heat called?

  Thermal decomposition