The changes in properties from metals to non-metals on a periodic table can be measured and determined by the metallicity or electropositivity of elements.
Metallicity is a measure of the tendency of atoms of an element to lose electrons.
a.
Down a periodic group, metallicity increases.
b.
Across a period from left to right electropositivity or metallicity decreases.
Metals are found in the left part of periodic table and the most reactive metal sits in the lower left corner. Non-metals are towards the right side of the table.
