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