Periodic Table Trends

Trends in Atomic Size

• As you move down a group, the atoms tend to get larger. (electrons are being added to larger orbitals and inner electrons tend to shield the nucleus so the outermost electrons tend to fell less pull or attraction from the nucleus)
•  And as you move across a period from left to right, the atomic size decreases. (adding more protons without much increase in shielding)

Trends in Ionization Energy

• Ionization energy- the energy needed to remove an electron from a gaseous atom
• removing an electron results in the formation of a cation
• The energy required for removal of the first electron is known as the first ionization energy. The energy required for removal of the second electron is known as the second ionization energy.

Trends in Electron Affinity

• Electron Affinity- the ease with which an electron many added to an atom, forming an anion
• Increases as you move up and to the right.
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Trends in Electronegativy

• Electronegativity of an element is defined to be the tendency of an atom to draw electrons toward itself when chemically combined with another element.
• Noble gases are not included

Difference between the two