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experiments prove disprove
publication further experiments
a pure substance consisting of only one kind of atom (ex copper) and can't be decompressed into simpler substances by normal chemical means
pure substances composed of atoms of different elements combined in definite, fixed ratios. And can be decomposed into simpler substances or elements by chemical means
properties that result in a chemical reaction converting the identity of one or more of the substances (flammability, anti-inflammatories, biodegradable)
properties that can be observed or measured with out changing the identity of the substances (boiling point, melting point, density, color)
process in which one or more pure substances are converted to one or more different pure substances
the smallest unit fo a chemical compound; the simplest structural unit of an element or compound
in a chemical formulas, numbers written below the line to show numbers or ratios of atoms in a compound
unit conversion factor
a fraction in which the numerator is a quality equal or equivalent to the quantity in the denominator, but expressed in different units
is the term used to express the agreement of the measured value with the true value of the same quantity
the number that represents the (weighted average) atomic mass of the isotopes in a given element (bottom number)
the regions around the nucleus within which the electrons have the highest probability of being found
In the electron configuration they are s (2 e- and 1 orbital), p (6 e- and 3 orbitals), d (10 e- and 5 orbitals) and f (14 e- and 7 orbitals)
metalloid elements with electrical conductivity intermediate between that of metals and nonmetals. Used in solid-state electronics
for metals is related to size, the larger the atom the more reactive it becomes, for nonmetals the opposite is true
Found that alpha rays could be stopped by thin pieces of paper. Whereas beta rays were only stopped by at least .5cm of lead
discovered the high energy, extremely penetrating gamma ray having characteristics of light waves. Very damaging to human issue.
the result of a natural change of an isotope of one element into an isotope of a different element resulting in a nuclear reaction.
radioisotopes are inserted into patients body allowing na image to be produced of the problem area.
lewis dot symbols
the valence electrons, represented by dots, are placed around the symbol until they are used up or unti all 4 sides are occupied
single covalent bond
hydrogen atoms share their single electron giving them an electron configuration like helium
hydrocarbon single bonds
one carbon and 4 hydrogen atoms will share electrons to achieve noble gas configuration
describes a bond or molecule in which charge is evenly distributed, with no positive or negative regions
describes a bond or molecule in which charge is unevenly distributed, creating positive and negative regions. Based on differences in electronegativity.
a compound that does not conduct electricity when melted or dissolved in water, or does not separate into ions in water
attraction between a hydrogen atom bonded to a highly electronegative atom (O, N, F) and an electronegative atom in another r the same molecule
Quantity of energy needed for successful collision of reactants; determines reaction rate.
condition in which a chemical reaction and its reverse are occurring at equal rates
Le Chatelier's principle
When a stress is applied to a system at equilibrium, the equilibrium shifts to relieve the stress
(of a chemical reaction or compound) occurring or formed with the release of energy as heat
(of a chemical reaction or compound) occurring only with energy as heat from an external source
a measure of the disorder of matter. If a change in entropy results in a more disordered state the entropy is said to be positive
First Law of Thermodynamics
energy can be converted from one form to another but cannot be created or destroyed
atom or groups of atoms in a molecule that gives the substance a characteristic chemical behavior
are reduced forms of matter which burn easily in the presence of oxygen producing large quantities of heat
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