Trends in the Periodic Table of Elements
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Transcript of Trends in the Periodic Table of Elements
TRENDS IN THE PERIODIC TABLE OF ELEMENTS
ATOMIC RADIUS
Based on the graph, what do you think Atomic Radius means?
ATOMIC RADIUS
Atomic Radius – size of an atom
ATOMIC RADIUS
It ________________ as you go down a column because:
increases
Electrons are added to a new energy level
ATOMIC RADIUS
It ________________ as you go across a row because:decreasesWithin an energy level, as you add
more protons (and electrons), the heavy protons pull the light electrons in closer
ATOMIC RADIUS
The corner of the Periodic Table with the highest atomic radius is
And the corner with the lowest atomic radius isLower left corner
Upper right corner
BEFORE WE MOVE ON…Atoms of all elements want to be stable
They will gain or lose electrons until their outer energy level is full (like the noble gases, column 18)
Ionization Energy – the amount of energy it takes to remove an electron
IONIZATION ENERGY
IONIZATION ENERGY
It ________________ as you go down a column because:
decreasesThe more total electrons an element has,
the less it cares about whether or not it loses one electron
IONIZATION ENERGY
It ________________ as you go across a row because:increases
The more valence electrons an element has, the more it wants to keep its electrons
IONIZATION ENERGY
The corner with the highest ionization energy is
The corner with the lowest ionziation energy isUpper right corner
Lower Left corner
IONIZATION ENERGY
Example) Which of the following elements has the highest ionization energy: sodium, argon, cesium, or radon? Argon
ELECTRONEGATIVITY
Electronegativity – how much an atom attracts electrons
Electronegativity
Atomic Number
ELECTRONEGATIVITY
It ________________ as you go down a column because:The more total electrons an element has, the less it cares about whether or not it gets another electron
decreases
ELECTRONEGATIVITY
It ________________ as you go across a row because:increasesThe more valence electrons an atom
has, the more it really wants another one to get closer to a full shell (column 18)
ELECTRONEGATIVITY
The corner with the highest electronegativity is
The corner with the lowest electronegativity is
Upper right (except noble gases)
Lower left
ELECTRONEGATIVITY
Example) Which of the following elements has the highest electronegativity: sodium, chlorine, rubidium, or iodine? Chlorine
ELECTRONEGATIVITY
Example) Place the following elements in order in terms of increasing (smallest to largest) electronegativity: silicon, sodium, chlorine. Sodium, Silicon,
Chlorine
ELECTRONEGATIVITY
Example) Place the following elements in order in terms of increasing (smallest to largest) electronegativity: lithium, sodium, cesium. Cesium, sodium,
lithium