the periodic table

how are elements arranged in the periodic table?

in vertical groups (group number = number of outer electrons)

in horizontal periods (period number = number of electron shells)

in order of increasing atomic number

what do the position of elements in the periodic table tell you?

group number - number of outer electrons

period number - number of electron shells

atomic number - number of protons = number of electrons

how can you use electrical conductivity and the acid-base character of oxides to classify elements as metals or non metals?

metals:

• conduct electricity

• good conductors

• forms a basic oxide

non metals

• do not conduct electricity

• poor conductors

• form an acidic oxide

what elements are on the line separating metals and non metals?

on the left side (metals) are Al, Ge, Sb, Po, and Lv

how is the electronic configuration of a main group element related to its position in the periodic table?

period number = number of electron shells

group number = number of electrons in the outermost shell

why do elements in the same group have similar chemical properties?

elements in the same group have the same number of outer electrons, which determines how an element reacts. Therefore, they react in similar ways and have similar chemical properties

why do the noble gases not readily react?

they have a full outer shell, so there is no tendency to lose, gain, or share elements in a chemical reaction. Therefore they are very unreactive.