Periodic Trends

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What is the electron configuration of neutral
1s222s
2s222p
2p663s
3s223p
3p33
phosphorous? 1s
Phosphorous is located here
How does atomic radius
change down a group
in the periodic table?
It tends to increase.
Atomic Trends
Why is the radius of a positive ION always
less than the radius of its NEUTRAL
atom?
It gave away an electron, and the nucleus
pulls the remaining electrons in closer.
Na neutral sodium
11 electrons
11 protons
Na 1+ sodium ion
10 electrons
11 protons
What term is used to describe an atom's
tendency to attract electrons (selfish of
electrons) to itself when it is chemically
combined with another element?
electronegativity
Really greedy because they are so
close to having 8 valence electrons.
Which group of the periodic table has the
highest electronegativity?
The
noble
7A, the halogens
More
greedy
for
electrons
gases
don’t
want or
do
much
More
greedy
for
electrons
Which of the following elements has the lowest
electronegativity (selfishness of electrons)?
Choose the cation with the least valence electrons and the
most amount of total electrons.
More
greedy
for
electrons
More
greedy
for
electrons
Electronegativity generally increases from
left to right across a period.
More
greedy
for
electrons
Compared with the electronegativities of the
elements at the left end of a particular
period,
the electronegativities of the elements at the
right side of that same period (ROW) tend
to be higher.
Which of the following factors contributes to
the relatively greater atomic size of the
higher-atomic-number elements within a
particular family of the periodic table?
More shielding of the outer electrons by the
inner electrons
Groups
(family or column)
• As we go down a
group each atom has
another energy level
• More shielding
• The outer electrons
have greater freedom
from the nucleus.
H
Li
Na
K
Rb
Which of the following
increases with
increasing atomic
number (GOING
DOWN) in Group 2A?
atomic radius…the
electrons have more
freedom to move
outward because of
shielding.
How does the shielding phenomenon affect
the relative atomic sizes of elements in the
same period (row)?
Shielding has no effect on relative atomic
size within a period.
Na
Mg
Al
Si
P
S Cl Ar
Which of the following
elements has the
smallest atomic
radius?
The one that is furthest
right.
Atomic size generally decreases as you
move from left to right across a period
(row).
The energy required to remove an electron
from a gaseous atom is called the
ionization energy.
Na neutral sodium
11 electrons
11 protons
Na 1+ sodium ion
10 electrons
11 protons
When is an electron configuration
particularly stable?
When its last principle energy level is a
filled.
For Group 3A metals, which electron is the most
difficult to remove from a neutral atom?
the fourth because it was meant to give away the
three in the valence shell, but the fourth is going
into an inner shell that was already stable.
Which of the following factors contributes to the huge ionization energy of
the elements on the right side of a period in the periodic table?
greater number of protons in nuclei and the number of valence electrons is
so close to the number 8
Don’t
want to
give away
electrons
Don’t
want to
give away
electrons
Which of the following elements has the smallest
FIRST ionization energy?
The elements in the 1A column because they are so
anxious to get rid of that one valence electron.
Don’t
want to
give away
electrons
Don’t
want to
give away
electrons
As you move from left to right across the
second period (row) of the periodic table
the ionization energy increases
Ionization energy increases because
they don’t want to give away electrons
Don’t
want to
give away
electrons
SIZE of atomic radius/diameter
Ionization energy needed & Electronegativity
SIZE of atomic radius/diameter
Ionization energy needed & Electronegativity
Of the following atoms, which one has the
smallest FIRST ionization energy?
pick positive cations before negative anions.
+1
+1
+1
+1
+1
+2
+2
+2
+2
+3
+3
Which of the following elements, would
ionically bind to sulfur?
metals bond with
non-metals for an ionic bond.
+1
+1
+1
+2
+2
+1
+2
+1
+2
+3
+3
S
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