Download CHAPTER 5 - THE PERIODIC LAW

CHAPTER 5 - THE PERIODIC LAW
5-1 History of the Periodic Table
___________________________ - created the first periodic table
- discoverer of the _________________________________________ - the
physical and chemical properties of the elements are periodic functions of
their atomic numbers
_________________________________ - recognized pattern where periodic table was arranged in increasing order
according to nuclear charge, or # of protons in nucleus.
- noted for reorganizing table by ______________________________
not atomic mass
The ______________________________________________is an arrangement of elements in order of their atomic
numbers so that elements with similar properties fall in the same column, or group
__________________________________ - unreactive
LANTHANIDES - 14 elements with atomic numbers from 58 (cerium, Ce) to 71 (lutetium, Lu)
- belongs in period 6
ACTINIDES - 14 elements with atomic numbers from 90 (thorium, Th) to 103 (lawrencium, Lr)
- belong in period 7
5-2 Electron Configuration and the Periodic Table
The electron configuration of an atom’s highest occupied _________________________ level governs the atom’s
chemical properties
The length of each ______________________________ is determined by the number of electrons that can occupy the
sublevels being filled in that period
Period number
1
2
3
4
5
6
7
Number of elements in period
2
8
8
18
18
32
32
Sublevels in order of filling
1s
2s 2p
3s 3p
4s 3d 4p
5s 4d 5p
6s 4f 5d 6p
7s 5f 6d, etc.
- the period of an element can be determined from the element’s electron configuration, arsenic, As, is
10
2
3
3d 4s 4p . The “4” indicates that arsenic’s highest occupied energy level is the fourth energy level
and therefore is in the fourth period
Table divided into 4 blocks: s, p, d, f
1) “s” - Groups ________________________________
- reactive metals, Group 1 more reactive than Group 2
- _______________________________________ = Group 1
- _________________electron in outermost s sublevel
- silvery appearance
- soft enough to cut with a knife
- not found in nature as ____________________________________________
- combine with vigorously with ____________________________________________________
- react strongly with _______________________ producing hydrogen gas and aqueous solutions of
substances known as alkalis
- stored in _____________________________________________
- melt at lower temps as go down group
- Group 2 - ____________________________________________________________
- _________________________________of electrons in outermost s sublevel
- harder, denser, and stronger than alkali metals
- higher melting points than alkali metals
- less __________________________________ than alkali metals
- too reactive to be found in nature as ____________________________________________
2) “d” -
Groups 3 - 12 - ______________________________________________________
the 3d sublevel is slightly higher in energy than the 4s so the 4s is filled before the 3d
have metallic properties
good conductors of ___________________________________________
high luster
less __________________________________ than the alkali metals and the alkaline earth metals
some are so ______________________________, Palladium, platinum, and gold, that they do not
easily form compounds
- exist in nature as ___________________________________________
3) “p” - Groups 13 - 18 - _______________________________________________ (must also include
the “s” block
- Helium is excluded
- an electron is added to the outermost energy sublevel as go across the period
- for atoms of p-block elements, the total number of electrons in the highest occupied level is
equal to the group number minus 10
- properties vary greatly
- right-hand end - ____________________________ , excluding hydrogen and helium
- _______________________________ - boron, silicon, germanium, arsenic, antimony,
and tellurium
- semiconducting elements
- ______________________________solids
- has properties of _____________________
and _________________________________
- left-hand end and bottom - ___________________________________
- harder and denser than the “s” block metals but softer and
less dense than the d block
- sufficiently reactive (excluding bismuth)
- found in nature only in the form of ___________________
- HALOGENS - ____________________________________
- most _____________________nonmetals (reason is they only have 7
electrons in outermost energy level
- react vigorously with most metals to form examples of the type of
compounds known as __________________________________
- Fluorine - gas at room temp
- Chlorine - gas at room temp
- Bromine - reddish liquid
- Iodine - dark purple solid
- Astatine - synthetic element (mostly known to be a solid)
4) “f” block - LANTHANIDES and ACTINIDES
- Lanthanides are shiny metals similar in reactivity to Group 2
- Actinides are all __________________________________________
- first four have been found naturally on Earth
- remaining are laboratory-made elements
Hydrogen - unique element
- resemble no other element
Helium - grouped with group _______________since highest energy level is filled
- ________________________________________________ in nature
- chemical stability
5-3 Electron Configuration and Periodic Properties
__________________________________________ - one-half the distance between the nuclei of identical atoms that
are bonded together
- _________________________________ going across periods,
caused by the increasing positive charge of the nucleus so are
gradually pulled closer to the more highly charged nucleus
- __________________________________ going down, since
the atom increases in size due to more energy levels and
electrons located farther from nucleus
________________________________________________________(IE) - energy required to remove one electron
from a neutral atom of an element
- _________________________________
across a period, due to increasing nuclear
charge
- ____________________________down
a group, the farther away the more easily
removed
- ____________________________ - any
process that results in the formation of an
ion
- ______________________ - an atom or
group of bonded atoms that has a positive
or negative charge
*****The ease of electron loss is a major reason for the high reactivity of Group 1
*****The energies for removal of additional electrons from an atom are referred to as the second
ionization energy, third ionization energy, etc. As electron are removed, fewer electrons
remain within the atom to shield the attractive force of the nucleus
__________________________________________- energy change that occurs when an electron is acquired by a
neutral atom
- atoms ________________________ energy when they acquire
an electron
-
-
A + e
A + energy
- atoms forced to _______________________ an electron by the
addition of energy
-
-
A + e + energy
A
- _____________________________________ across periods
- _________________________________________down groups
_______________________________ - CATION - positive ion
- formation of a cation by the__________________of one or more electrons
always leads to a ___________________________ in atomic radius because
the removal of the highest-energy-level electrons results in a smaller
electron cloud and remaining electrons are drawn closer to nucleus
- ANION - negative ion
- formation of an anion by the ____________________________________of
one or more electrons always leads to an ____________________________
in atomic radius because the total positive charge of the nucleus remains
unchanged when an electron is added to an atom or an ion and the electron
cloud spreads out because of greater repulsion between the increased
number of electrons
- ________________________________radii ______________________across a period due to the
electron cloud shrinking due to increasing nuclear charge acting on the electrons in the same
main energy level
- _________________________________radii ___________________________________ across
each period for same reason cations decrease
- for both, ________________________________________down a group
_________________________________________________________________ - electrons available to be lost,
gained, or shared in the
formation of chemical
compounds
- groups 13 - 18 have a number of
valence electrons equal to the
group number minus 10
_________________________________________________________ - measure of the ability of an atom in a
chemical compound to attract electrons
- _____________________across periods
- _____________________________down
groups or remain about the same
- ________________________________
mostly do not form compounds and
therefore are not assigned
electronegativities but for those that do, they
are very high