chem reactions (notes)

Created by

Julia Beadle

Cards (19)

Chemical reaction
At least one substance is changed into a different substance. This transformation happens when chemical bonds break, the atoms are rearranged, and new chemical bonds are formed.
Chemical changes
signs of a chem change include color, odor, pH (acidity level), temperature change
Precipitates
Solid substances that can be formed when liquid substances are combined
Gases can also be formed from chemical reactions
Changing state is not a chemical reaction but a physical change
Law of conservation of energy 
Energy can change from, but can't be created or destroyed
Chemical reactions in open loop systems 
The output does not feed back into the system, energy is always entering and exiting the chemical reaction
Energy in chemical reactions
Sometimes the energy is required as a reactant, sometimes it is a product, and sometimes it's both. Energy is needed to break and form the chemical bonds between the atoms.
Exothermic reactions
Release excess energy in the form of light, heat, or even sound
Endothermic reactions 
Require more energy then they produce, which can leave the containers these reactions occur in feeling cold
Reactant 
A substance that takes part in and undergoes change during a reaction
Product 
A new material formed in a chemical reaction
Law of conservation of matter 
Matter can't be created or destroyed, can only change form
Physical property
A property of a substance that can be observed without changing the substance's identity
Chemical property 
A characteristic that describes the atomic or elemental composition of a substance – It can be observed during a chemical reaction
Atomic particles 
Determine the chemical and physical properties of an element
The reaction will continue until at least one of the reactants is used up
Catalyst 
A chemical that accelerates a chemical reaction without being consumed in the reaction
There will be the exact same amount of the catalyst at the end of the reaction as at the beginning