Chapter 4 study guide Flashcards
the smallest particle of an element
atom
negatively charged particles
electron
a tiny region in an atoms center
nucleaus
positively charged particles in the nucleus
proton
the specific amount of energy an atom has
energy level
a particle that has no electrical charge
neutron
the number of protons in the nucleus of an atom
atomic number
the different number of protons in an atom
isotope
the sum of the protons and the neutrons in the nucleus of an atom
mass number
the average mass of all the isotopes in an element
atomic mass
an arrangement of elements showing the repeating pattern of their properties.
periodic table
the horizontal rows of the periodic table
period
the vertical columns in the periodic table also sometimes called families.
group
a representation of an element usually consisting of on or two (sometimes 3) letter
chemical symbol
elements that are good conductors of electric and thermal energy
metal
this kind of material is one that can be hammered or rolled into flat sheets or other shapes
malleable
this kind of material is one that can be pulled out, or drawn, into a long wire
ductile
the ability of an object to transfer heat
thermal conductivity
The ability of an object to transfer electric current
electrical conductivity
the ease and speed with which a substance reacts with other substances
reactivity
the gradual wearing away of a metal due to a chemical reaction
corrosion
The metals in Group 1, from lithium to francium
alkali metal
Group 2 of the periodic table
alkaline earth metal
the elements in groups 3-12
transition metal
these powerful machines move atomic nuclei faster and faster until they have reached very high speeds
particle accelerator
an element that lacks most of the properties of a metal
nonmetal
a molecule that consists of two atoms, such as oxygen O2
diatomic molecule
Group 17 which contains fluorine, chlorine, bromine, iodine, and astatine, means “salt forming”
halogen
the elements in group 18
inert gas
have some properties of metals but also, have properties that are typical of nonmetal
semimetal
substances that can conduct electricity
semiconductor
in this process, the atomic nuclei of unstable isotopes release fast-moving particles and energy
radioactive decay
when something spontaneously gives off radiation
radioactivity
a positively charged particle that consists of two protons and two neutrons
alpha particle
a fast-moving electron that is given off by a nucleus during radioactive decay
beta particle
radiation that consists of high-energy waves, similar to X-rays
gamma radiation
radioactive isotopes that can be followed through the steps of a chemical reaction or an industrial process
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