CHEM 21.31 - Module 1.6 Periodic Trends in Atomic Properties

1. atomic size

2. ionization energy

3. electron affinity

name 3 periodic trends in atomic properties

valance shell

where valance electrons are found and affects atomic size

the atomic size increases

what happens if the valance shell is a larger number?

valance shell increases from top to bottom in a group

pattern of valance shell for groups from top to bottom

nuclear charge

strength of interaction between nucleus and valance electrons

atomic size decreases

what happens if the nuclear charge increases?

nuclear charge increases from left to right

pattern of nuclear charge for left to right across a period

ionization energy

energy required to remove an electron from gaseous atom

easier to remove first ionization energy

pattern for ionization energy as valance electrons move further from nucleus

electron affinity

energy required to place an electron on a gaseous atom

electron affinities increase (more negative) from left to right for a period and bottom to top for a group

electron affinity pattern on periodic table

light emitting diode

emits monochromatic light

monochromatic light

light of a single wavelength/color

lasers

emits coherent light and direct result of quantum mechanical model of atom

coherent light

all light waves are perfectly in phase and go through maxima and minima together