Exothermic and Endothermic
This energy from this type of reaction is often released through heat.
Exothermic
When groups of atoms combine together, they are referred to as...
Molecules
One of the three types of subatomic particles. [Has a positive charge]
Protons
A new substance formed in a chemical reaction.
The three groups of elements on the periodic table.
Metals, metalloids, and nonmetals
A molecule that speeds up chemical reactions.
Catalyst
H2O is an example of a...
Chemical formula
All matter is composed of...
Atoms
A change in matter that does not result in a new substance.
Physical change
Horizontal rows on the periodic table
Periods
Photosynthesis is an example of this type of reaction.
Endothermic reaction
This rule states that atoms bond in order to have a full valence shell of eight electrons.
Octet Rule
Nucleus
This law states that matter is never created nor destroyed.
The Law of Conservation of Mass
Electrons involved in chemical reactions.
Chemical reaction that uses more energy than it releases.
Endothermic Reactions
A chemical bond formed by atoms sharing one or more electrons.
Covalent bond
This type of subatomic particle has no mass.
Electron
If a chemical change has happened, a ___ happened as well.
Chemical reaction
Activation Energy
Why do chemical bonds form?
To reach a lower state of energy [Increases stability and releases energy]
This scientist concluded that electrons were scattered throughout an atom.
J.J. Thomson
Precipitate
Alkali metals