This document discusses chemical reactions and equations. It explains that chemical reactions involve substances changing partners to form new substances, while conserving mass. Chemical equations are used to represent these reactions, showing the reactants, products, and phase changes. The document also discusses how energy is often either released or absorbed during chemical reactions, depending on whether the bonds in the products are more or less stable than the reactants. Key terms like endothermic and exothermic are introduced to describe reactions that absorb or release thermal energy.
19. Conserve That Mass
The mass of the products must be the
same as the mass of the reactants in
the chemical reaction.
20. Conserve That Mass
The mass of the products must be the
same as the mass of the reactants in
the chemical reaction.
Atoms are never lost of created in a
chemical reaction; however they do
change partners.
28. Energy Released
Where does this energy come from?
You have to think about the chemical bonds of
the reactants and the products, in order to
answer this question.
29. Energy Released
Where does this energy come from?
You have to think about the chemical bonds of
the reactants and the products, in order to
answer this question.
When energy is released, the products are more
stable, and their bonds have less energy than
those of the reactants.
30. Energy Released
Where does this energy come from?
You have to think about the chemical bonds of
the reactants and the products, in order to
answer this question.
When energy is released, the products are more
stable, and their bonds have less energy than
those of the reactants.
The extra energy is released in different forms:
light, sound, thermal energy
32. Energy Absorbed
When energy is absorbed, the reactants are
more stable, and their bonds have less energy
than those of the products.
33. Energy Absorbed
When energy is absorbed, the reactants are
more stable, and their bonds have less energy
than those of the products.
The extra energy needed to form the products
can be supplied in the form of electricity, light,
sound, thermal energy.