Chemistry words Flashcards
Activation Energy
the minimum energy required to initiate a reaction
Alloy
a mixture of two or more metals, Common alloys are steel, brass and bronze. Gold jewelry is an alloy, the amount of alloy is expressed in karats. Each karat is 1/24, hence 24 karat gold.
Anion
A negatively charged ion
Boiling
A phase change from a liquid to a gas
cation
a positively charged ion
chemical change
a change that results in an new substance with new chemical and physical properties, burning and rusting
combustion
an exothermic chemical reaction, burning
compound
a substance composed of 2 or more different elements chemically combined in a definite ratio. A compound can be decomposed by a chemical
condensation
the change in a state of matter from a vapor to a liquid. Condensation of water vapor during cloud formation releases large amounts of energy to the atmosphere
covalent bond
a chemical bond formed when atoms share electrons, (example CO2)
decompostiton
A chemical reaction in which the reactants are broken apart;the chemical breakdown of a substance onto simpiler substances
entropy
a quantitative measure of the disorder of a system. there is a tendency in nature to proceed toward a state of greater disorder. the entropy of the universe is steadily increasing
freezing
the change in phase of a substance from a liquid to a solid state. the substance releases energy
gas
a phase of matter that has no definite shape or volume. A gas takes the shape of its container entirely
melting point
the temperature at which a phase change occurs from solid to liquid; the same as the freezing point. When a solid melts, it absorbs heat energy and changes to the liquid phase. The amount of heat required to accomplish this phase change is called heat of fusion
