Journal Questions. Define Valence Electron . What is the significance of valence electrons? Use your periodic table to figure out how many valence electrons Magnesium has. Explain Magnesium’s reactivity using it’s valence number. Periodic Table.
The group number is an identifier used to describe the column of the standard periodic table in which the element appears.
Groups 1-2 (except hydrogen) and 13-18 are termed main group elements.
Groups 3-11 are termed transition elements. Transition elements are those whose atoms have an incomplete d-subshell
Groups are Numbered (How many groups are there on the PT? )
Group number tells how many valence electrons
A Group is called a Family – elements in the same family React the same
Show how many electron shells there are
how many periods are there?
atomic number increases from left to right