The Foundations of Chemistry Flashcards
Key terms in foundation chemistry
Accuracy
How closely a measured value agrees with the corerect value.
Atom
The smallest particle of an element that maintains its chemical identity through all chemical and physical changes.
Atomic number
The number of protons in the nucleus of an atom.
Calorie
Defined as exactly 4.184 joules. Originally defined as the amount of heat required to raise the temperature of one gram of water from 14.5°C to 15.5°C.
Chemical change
A change in which one or more new substances are formed; also known as chemical reaction or just reaction.
Compound
A substance composed of two or more elements in fixed proportions. Compounds can be decomposed into their constituent elements.
Density
Mass per unit volume, D = m/V.
Element
A substance that cannot be decomposed into simpler substances by chemical means.
Endothermic
Describes processes that absorb heat energy.
Energy
The capacity to do work or transfer heat.
Exothermic
Describes processes that release heat energy.
Extensive property
A property that depends on the amount of material in a sample.
Heat
A form of energy that flows between two samples of matter because of their difference in temperature.
Heat capacity
The amount of heat required to raise the temperature of a body one degree Celsius.
Heterogeneous mixture
A mixture that does not have uniform composition and properties throughout.
