1c Students know how to use the periodic table to identify alkali metals alkaline earth metals and transition metals trends in ionization energy electronegativity and the relative sizes of ions and atoms ID: 538054
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Slide1
Atomic Size, Ionization Energy, & Electronegativity
1.c. – Students know how to use the periodic table to identify alkali metals, alkaline earth metals and transition metals, trends in ionization energy, electronegativity, and the relative sizes of ions and atoms.
Periodic Table TrendsSlide2
Periodic Law
Mendeleev understood the ‘
Periodic Law
’ which states:
“When arranged by increasing atomic number, the chemical elements display a regular and repeating pattern of chemical and physical properties”.Slide3
Atoms with similar properties appear in groups or families (vertical columns) on the periodic table.They are similar because they all have the same number of valence (outer shell) electrons, which governs their chemical behavior.
Periodic Law Continue
Families or Groups share similar chemical and physical properties!
Are Elements in a Row or Period Alike?Slide4
There are several other important atomic characteristics that show predictable trends that you should know.
Atomic size
Ionization Energy
Electronegativity
Periodic Law ContinueSlide5
Atoms at the bottom of the periodic table are BIGGER
than atoms at the top!
Atomic Size
WHY DO
ATOMS
GET BIGGER AS YOU GO DOWN A GROUP?Slide6
nucleus
E
1
E
2
E
3
E
4
1
2
3
4
5
6
7
E
6
E
5
E
7
Energy Levels are Added…Making the Atom Bigger!Slide7
As we go down a group each atom has another energy level…So the atoms get bigger.
H
Li
Na
K
Rb
What happens as we go across a Period?Slide8
Atoms on the left side of the periodic table are bigger than atoms on the right side of the periodic table.
what increases as we go across a row?Slide9
As we move across a period….protons are added….this increases the nuclear charge (+)!
As protons are added….electrons are also added….so the electrostatic attraction increases (positive & negative attraction)!This attraction pulls the outermost electrons in closer to the nucleus….making the atom smaller!
+
_
+
_
Na
Mg
Al
Si
P
S
Cl
ArSlide10
Atomic size tends to increase from right to left and from top to bottom.
Atomic Size
Increases
Atomic Size
Increases
Slide11
Ionization Energy - amount of energy needed to remove an electron from an atom.
Ionization Energy
Is it harder to take electrons from elements that want to lose e- or elements that wants to gain e-?Slide12
It is harder to remove an electron from smaller atoms because the nucleus is closer and better able to hold on to them.
It is easier to take electrons from larger atoms because the electrons are further from the nucleus. It is easier to take electrons from metals since they want to LOSE electrons!
Alkali metal
Halogens
Noble Gases
LOW IONIZATION ENERGY
Medium-High IONIZATION ENERGYVery High IONIZATION ENERGYSlide13Slide14
Ionization Energy tends to increase from left to right and from bottom to top.Slide15
Electronegativity - ability of an atom to attract an electron.
ElectronegativitySlide16
It is easier for small atoms to attract an electron because the nucleus is closer and is better able to hold on to them.
It is easier for nonmetals to gain electrons.
Which element has the highest electronegativity?Slide17
Electronegativity
tends to increase from left to right and from bottom to top.Slide18
Putting It All Together
Metals
Metalloids (Semimetals)Nonmetals
Left Side
Alkali
Alkaline Earth
TransitionElements dividing the metals and nonmetals (stair-step line)Right SideHalogensNoble GasesGive up (Lose) e-CationsGive up (Lose) e- Or Accept (Gain) e- Accept (Gain) e-Anions Big Atomic SizeSmall Atomic SizeLow IonizationHigh IonizationLow ElectronegativityHigh Electronegativity(Excluding Noble Gases)
(Noble gases do not gain e-)Slide19
Cornell Questions
As you move across a Period, how does the atomic number change?As you move across a Period, how does the “pull” of the nucleus on the electrons change?As you move across a Period, how does the atomic size, ionization energy, and electronegativity change?
As you move down a Group, how does the atomic size, ionization energy, and electronegativity change?Slide20
Atomic Size
Increases
IncreasesSlide21
Increases
Increases
Ionization Energy
ElectronegativitySlide22
Create a Periodic Table Trends Periodic Table
Number the rows and groupsDraw increasing arrows representing atomic size (must be in color)Draw increasing arrows representing ionization energy (must be in a different color)
Draw increasing arrows representing electronegativity (must be in a different color)