6-1 Song chemical changes
6-1 Notes
Chemical reactions change substances
An indicator of chemical change include-
Production of gas
Color change
Release of heat
Chemical reactions only rearrange atoms
Reactant - in a chemical reaction, is the substance you start with before the reaction.
Products - in a chemical reaction is the substances formed by the reaction.
2Na + Cl2 yields 2NaCl (New product atoms are not created, and old reactant atoms are not destroyed)
Forming bonds release energy. The total energy before the reaction is equal to the energy to the total energy of the products and their surroundings.
Exothermic reactions release energy.
Temperature rises because energy is released from the chemical energy of the reactants. (combustion reaction)
Endothermic reactions absorb energy.
A chemical reaction that requires the addition of heat to proceed : thus the reaction absorbs heat from its surroundings. (photosynthesis)
An indicator of chemical change include-
Production of gas
Color change
Release of heat
Chemical reactions only rearrange atoms
Reactant - in a chemical reaction, is the substance you start with before the reaction.
Products - in a chemical reaction is the substances formed by the reaction.
2Na + Cl2 yields 2NaCl (New product atoms are not created, and old reactant atoms are not destroyed)
Forming bonds release energy. The total energy before the reaction is equal to the energy to the total energy of the products and their surroundings.
Exothermic reactions release energy.
Temperature rises because energy is released from the chemical energy of the reactants. (combustion reaction)
Endothermic reactions absorb energy.
A chemical reaction that requires the addition of heat to proceed : thus the reaction absorbs heat from its surroundings. (photosynthesis)
6-1 Summary
During a chemical reaction, atoms are rearranged.
Signs of a chemical reaction include any of the following.
a substance that has different properties than the reactants have
a color change
the formation of a gas or a solid precipitate
transfer of energy
Mass and energy are conserved in a chemical reactions
Energy can be released or absorbed in a chemical reaction.
Energy must be added to the reactants for bonds between atoms to be broken.
Signs of a chemical reaction include any of the following.
a substance that has different properties than the reactants have
a color change
the formation of a gas or a solid precipitate
transfer of energy
Mass and energy are conserved in a chemical reactions
Energy can be released or absorbed in a chemical reaction.
Energy must be added to the reactants for bonds between atoms to be broken.