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### Periodic Table Trends

Posted: Fri Oct 19, 2018 11:14 pm
Could someone explain how to use the periodic table to predict and explain trends in atomic radius, ionic radius, ionization
energy, and electron affinity?

### Re: Periodic Table Trends

Posted: Sat Oct 20, 2018 12:49 am
As you go down a group, the atomic radius increases because the electrons are at larger distances from the nucleus. As you move across a row, the increased amount of protons pull the electrons closer, making it harder to remove (since protons in nucleus attract) and therefore increase IE. Moving down a row decreases IE because the distance electrons are from the nucleus increases. Electron affinity increases across a row because of a decrease in atomic radius, but decreases down a group because of increasing atomic radius.

### Re: Periodic Table Trends

Posted: Sun Oct 21, 2018 1:22 pm
ATOMIC RADIUS- increases down and to the left
IONIZATION ENERGY & ELECTRON AFFINITY-increases up and to the right
metals are on the left and nonmentals are on the right

### Re: Periodic Table Trends

Posted: Sun Oct 21, 2018 4:22 pm
Atomic radius increases down and to the left on the periodic table because electrons are farther away from the nucleus. Ionization energy decreases farther down the periodic table because it is easier to remove an electron when they are farther away from the nucleus. Electron affinity increases up and to the right because the atoms want to get to a full set of valence electrons (similar concept to electronegativity).

### Re: Periodic Table Trends

Posted: Sun Oct 21, 2018 11:52 pm
Just looking at the periodic table doesn't typically help in understanding trends in the table itself. One way I would recommend looking at it is just looking up graphs and images representing the changes!

### Re: Periodic Table Trends

Posted: Sun Oct 21, 2018 11:59 pm
Atomic radius gets bigger and farther down to the left. Ionic Radius gets bigger farther down to the left, but there isn't a strong correlation. Electron affinity gets stronger to the left and ionization energy gets larger to the right.