Mecanics of Chemical Equations
Reactants, indicating heat products and coefficients and catalysts
" Substances (elements and/or compounds) called reactants are changed into other substances (compounds and/or elements) called products.
an arrow is used to indicate that a chemical reaction has taken place.Reactants→Products
The chemical equation that represents this reaction is written like this:
The 2 in front of the oxygen gas and the 2 in front of the water vapor are called the reaction coefficients. They indicate the number of each chemical species that reacts or is formed.
Methane and oxygen (oxygen is a diatomic — two-atom — element) are the reactants, while carbon dioxide and water are the products.
A lot of reactions are exothermic. Some reactions, however, absorb energy rather than release it. These reactions are called endothermic reactions."
States of matter
In a solid, particles are packed tightly together, generally can't move from place to place
Molecules are close together without an arrangement , may vibrate and move
Molecules are well separated, moves at high speed