scientists who used the words “element” and “atom”
Greek thinkers
scientists who wrote the first extensive list of elements containing 33; distinguished between metals and non-metals and divided them into four classes
Lavoisier
scientists suggested the mass of an atom was its most impt. property
john dalton
noted that similar elements had relative atom masses, grouping elements in “triads”
doberiner
scientists who came up with 3d periodic table and placed elements in unbroken order of increasing weight of the atoms
dechancourtois
determined atom weights for the elements known in the 1860s
Cannizaro
scientist who arranged a table and came up with the Law of Octaves
newlands
scientist who compiled a periodic table of 56 elements based on the periodicity of properties such as molar volume when arranged in order of atomic weight
meyer
scientist who universally is thought of as the sole originator of the periodic table; more interested in chemical properties
mendeleev
scientist who reordered the table according to atomic numbers rather than weight; modified periodic law
moseley
created the Actinide series
seaborg
why are the elements placed in specific places on the periodic table?
the way they look and act
periods are _____ that run from ____ to ______
rows, left, right
elements in the same period have the same ________________
number of atomic orbitals
every element in the first period has ________ shell for its ________. every element in the second period has _________ for its ____________
one orbital, electrons, 2 orbitals, electrons
groups are _____ that run from ________ to _________
columns, top, bottom
the elements of a group have the same number of _________ in their ______ shell
electrons, outer
every element in group one has _______ electron in its outer shell
one
every element in group two has ______ electrons in its outer shell
two
hydrogen is special because it can act like two groups: ________ and _______
one, seven
hydrogen sometimes is __________ an elctron and sometimes it has an _________ electron
missing, extra
although helium has only ____ electrons in its outer shell, it is grouped with elements that have ________
two, eight
the green elements on this table are called __________ elements. they each have two electrons in their outer shell
transition
what is the group number for alkali metals?
one
are alkali metals reactive?
yes
do alkali metals occur freely in nature?
no
how many electrons are in alkali metals’ outer shell?
one
what are three characteristics of all metals?
malleable, ductile, good conductors of heat and electricity
are alkali metals soft or hard?
soft
name the two most reactive elements in the alkali metal group
cesium and francium
what happens when alkali metals are exposed to water?
they can explode
what is the group number for alkaline earth metals?
two
are alkaline earth metals reactive?
yes
do alkaline earth metals occur freely in nature?
no
how many electrons are in alkaline earth metals’ outer shell (same as their oxidation or group number)
two
how many elements are in the transition metals’ group?
38
what are the group numbers of the transition metals?
3 through 12
what are valence electrons?
electrons used to combine with other elements
because the valence electrons are present in more than one _____, transition metals often exhibit several common _____________
shell, oxidation states
name three elements in the transition metals that produce a magnetic field
iron, cobalt, nickel
how many elements are in the group: other metals?
7
what are the group numbers of “other metals”
13 through 15
how are these other metals similar to the transition metals?
ductile and malleable
how are other metals different than the transition metals?
do not exhibit variable oxidation states, valence electrons are only present in outer shell
list three physical properties of these other metals
solid, high density, opaque
what are the oxidation numbers for the group: other metals?
+3, +-4, -3
metalloids have properties of both _______ and _________
metals, nonmetals
carry an electrical charge under special conditions
semiconductor
name two metalloids that are semi-conductors
silicon, germanium
metalloids are useful in _______ and _________
computers, calculators
what are the group numbers of nonmetals?
14 through 16
list four characteristics of ALL nonmetals
not able to conduct electricity or heat very well, very brittle, cannot be rolled into wires or pounded into sheets
what tow states of matter do nonmetals exist in at room temperature?
gases and solids
nonmetals have no ________ and do not ________
metallic luster, reflect light
what are the oxidation numbers of nonmetals?
+-4, -3, -2
what is the halogen group number?
17
are halogens metals or nonmetals?
nonmetals
the term “halogen” means _____ and compounds containing halogens are called _________
salt-former, salts
how many electrons are in halogens’ outer shell?
7
what are halogens’ oxidation number
-1
what states of matter do halgoens exist in at room temperature?
solid, liquid, gas
what is the group number for noble gases
18
are noble gases inert or stable? why?
inert b/c their oxidation number prevents them from forming compounds readily
how many rare earth elements are there?
30
synthetic or man-made
trans-uranium
the Rare Earth metals are found in group _____ and periods __ and ____
3, 6, 7
