Chemistry Review Flashcards
positive charge, mass of 1 AMU, in nucleus, decides identity (element) of atom
proton
no charge, mass of 1 AMU, in nucleus
neutron
negative charge, no relevant mass, in electron cloud, decides how atoms bond with one another
electron
Anything that has mass and takes up space.
matter
A characteristic of a pure substance that can be observed without changing the substance’s composition.
physical properties
A property of matter that describes a substance’s ability to participate in chemical reactions.
chemical properties
A substance that cannot be broken down into simpler substances, and are the primary constituents of matter.
element
Smallest unit (particle) of an element
atom
An atom’s central core, containing protons and neutrons. Has virtually all of its mass.
atomic nucleus
The region around the nucleus of an atom where electrons are likely to be found.
electron cloud
the number of protons in the nucleus of an atom
atomic number
A one or two letter abbreviation for an element.
atomic symbol
the weighted average of the masses of the isotopes of an element
atomic mass
atoms of the same element that have different numbers of neutrons
isotope
a charged atom; gains its charge by having a different number of protons and electrons
ion
the sum of the number of neutrons and protons in an atomic nucleus; the mass of a specific atom
mass number
electrons on the outermost energy level of an atom
valence electrons
Hydrogen has ___ valence electrons.
one
Nitrogen has ___ valence electrons
five
Chlorine has ___ valence electrons.
seven
Calcium has ___ valence electrons.
two
Xenon has ___ valence electrons.
eight
Gallium has ___ valence electrons.
three
two or more atoms joined together chemically
molecule
molecule formed by the chemical combination of two or more elements
compound
Symbols that show the elements in a compound and the ratio of atoms
chemical formula
different orbits that electrons can take around the nucleus
electron shells (energy levels)
electrons move in fixed in circular orbits around nucleus of an atoms
Bohr’s model
Diagram of an atom, ion or molecule in which each dot represents a valence electron
Lewis Dot Diagram
refers to an outer main energy level occupied, in most cases, by eight electrons
noble gas configuration
in forming compounds, atoms tend to achieve the electron configuration of a noble gas, 8 valence electrons
octet rule
Formed when one or more electrons are transferred from one atom to another
ionic bond (definition)
A chemical bond that involves sharing a pair of electrons between atoms in a molecule
covalent bond (definition)
metal + nonmetal
ionic bond (atom types)
nonmetal + nonmetal
covalent bond (atom types)
A starting material in a chemical reaction
reactants
Ending materials in a chemical reaction.
products
A combination of two or more substances that are not chemically combined
mixture
A mixture that is not uniform in composition; components are not evenly distributed throughout the mixture
heterogeneous mixture
A mixture in which substances are evenly distributed throughout the mixture
homogeneous mixture
A homogeneous mixture of two or more substances
solution
in atomic notation, the lower-left number
atomic number, number of protons
in atomic notation, the upper-left number
mass number, protons + neutrons
in atomic notation, the upper-right number
charge, protons - electrons
MgO would have:
ionic bonds
NO would have:
covalent bonds
Atomic notation, # of protons
The atomic number, bottom left
Atomic notation, # of neutrons
The mass number, top left, minus the number of protons
Atomic notation, # of electrons
The number of protons minus the charge
a material with only one element of atom present, such as pure copper (Cu)
pure substance, element
a material with only one kind of compound present, like pure salt (NaCl)
pure substance, compound
