Transcript File - Science with Mr. Louie

Periodic Trends
- Atomic weight increases from left to right
and top to bottom because atoms increase
in the number of protons and neutrons
Periodic Trends
- Atomic size/radius increases from top to bottom
because of the addition of shells in groups
-Atomic size/radius decreases from left to right
because electrons remain the same distance away
from the nucleus in a shell, but the number of
protons increases which leads to electrons pulled
further in and thus smaller radii in periods
Periodic Trends
-Electronegativity is the ability of an
atom to pull electrons to itself
-a higher electronegativity means that
the atom is able to pull electrons to itself
very well
-a lower electronegativity means the
atoms is not able to pull electrons to
itself very well
Periodic Trends
-Electronegativity increases from left to
right and decreases from top to bottom
-explanation: more protons with less
shells leads to an atom that can pull
electrons away from other atoms very
well
Periodic Trends
-Ionization energy is the
energy required to pull an
electron away from the
outermost shell of an atom
-a higher ionization energy
means it is harder to pull an
electron away from that atom
-a lower ionization energy
means that it is easier to pull
an electron away from that
atom
Periodic Trends
-ionization energy trends follow similar
patterns to electronegativity (ie. increases
left to right and bottom to top
-if an atom is able to pull electrons to
itself well, it will likewise not easily give
up electrons
Periodic Trends
-explanation:
-shielding effect (group): more shells create a
“shielding” effect that diminishes the force of
the nucleus on the outermost e-electrons remain the same distance away
from the nucleus in a shell, but the number of
protons increases which leads to greater
attraction