2 Changes in Matter Flashcards
(21 cards)
physical change
any change that alters the form or appearance of matter but does not make any substance in the matter into a different substance.
Example: Water is still H2O even when it’s frozen into ice or evaporated into steam.
4 kinds of physical changes
A change in the state, shape, color or size
chemical change
A change in matter that produces one or more new substances – with properties different from those of the original substances
chemical reaction
same as “chemical change of state”
4 kinds of chemical changes
combustion, electrolysis, oxidation, and tarnishing
Law of Conservation of Matter
matter is not created or destroyed in any chemical or physical change.
mass
the measurement of the amount of matter
energy
the ability to do “work” or cause change
4 kinds of energy
thermal energy, chemical energy, electromagnetic energy, and electrical energy (think up an acronym: TCEE or ETCE or CEET or TEEC…)
temperature
a measure of the average energy of random motion of particles of matter
thermal energy
the total energy of all the particles in an object. Thermal energy always flows from warmer matter to cooler matter.
direction of thermal energy
Thermal energy always flows from warmer matter to cooler matter.
2 kinds of thermal energy
endothermic and exothermic
exothermic energy
Example: energy is given off / out, such as in combustion
endothermic energy
Example: energy is absorbed inward, such as a melting ice cube
chemical energy
the energy stored in the chemical bonds between molecules
electro-magnetic energy
a form of energy that travels through space as waves
Example: visible light
electrical energy
the energy of electrically charged particles moving from one place to another
electrolysis
splitting the molecules of water into Hydrogen and Oxygen, using electricity to break the bonds of H2O.
electrode
a metal strip
transforming energy (from one type to another)
Chemical energy may be changed to other forms of energy during a chemical reaction. Or, other forms of energy may be changed into chemical energy.
