Notes Reactivity Energy Levels Valence electrons n Valence

Notes: Reactivity

Energy Levels - - - - - - -

Valence electrons n Valence electrons are electrons in the atom’s last energy level n Valence electrons are used in chemical bonds.

What is a group/family? A column in the periodic table. n The elements in a family have similar properties. n

What do all elements in a group have in common? n The number of valence electrons n Valence electrons are electrons in the atom’s last energy level

Notice each column has the same number of valence electrons 8 is the Maximum, which what the inert gases

How are valence electrons used? n Valence electrons are what connect atoms together to form molecules. n All atoms want their energy levels filled.

Reactivity n Reactivity describes how much an atom wants to create a bond with other atoms.

Chemical bond A chemical bond is a connection between atoms through their electrons. H 2 O 2

˜ ˜ O How many ˜ ˜ H ˜ How many ˜ valence electrons does oxygen now have? H

High reactivity n The closer they are having the maximum valence electrons the more they want to bond. Na reactive One away= very

What makes inert gases special? Maximum electrons = NOT reactive He Ne

Which groups are the most reactive?

To Summarize: A family/group is a vertical column. n All the elements in a group have the same number of valence electrons. n Valence electrons are used when atoms bond together. n Valence electrons determine reactivity. n Inert gases have no reactivity. n