Praxis Middle School Science-Periodicity Flashcards
periodic table of elements
a tabular arrangement of elements in rows and columns, highlighting the regular repetition of properties of the elements
if the elements are arranged in rows and columns by atomic number…
the elements in each vertical column have similar properties
period
the elements in any one horizontal row of the periodic table
group
the elements in any one column of the periodic table
metal
a substance or mixture that has a characteristic luster, or shine, and is generally a good conductor of heat and electricity
malleable
can be hammered into sheets
ductile
can be drawn into wire
nonmetal
an element that does not exhibit the characteristics of metal; most are gases, and the ones that are solids are generally hard and brittle
metalloids
elements having both metallic and nonmetallic properties
alloy
a mixture of two or more elements having properties of metals, but are not necessarily all metals
with the exception of hydrogen, all group 1 are
alkali metals
shiny, softer, and less dence
the most chemically active of all metals
they react with water
group 2 metals are
alkaline earth metals
harder, denser, have higher melting points
chemically active
groups 3-12
transition elements
metals that include silver, gold, and mercury
hard and have high melting points
compounds are often colorful
lathanide series
one of the bottom rows
metals
used in making alloys
actinide series
radioactive elements
nonmetals
not shiny, brittle, not good conductors of heat and electricity
solids, gases, and one liquid (bromine)
group 17
halogens
combine readily with metals to form salts
group 18
noble gases
they do not react chemically with other elements
do not mix with the masses
these gases are inert (inactive) and will combine with other elements only under very specific conditions
metalloid physical properties
- all are solids having the appearance of metals
- all are white or gray, but not shiny
- all will conduct electricity but not as well as metal
metalloid chemical properties
they have some characteristics of metals and nonmetals
-their properties do not follow patterns like metals and nonmetals; each must be studied individually
semiconductors
typically a metalloid used in electrical devices that have to function at temperatures too high for metals
the number of placement and energy level of an atom’s electrons determines how…
that atom will react with other atoms
electron affinity
the readiness of an element to attract and hold an extra electron
