introduction to periodic table and atomic stability Flashcards
what are periods
horizontal rows
seven
numbered using arabic numbers
elements in same period all have same number of occupied electron shells
groups
vertical columns
mainly eight
numbered using roman numerals
for groups 1 to 7 number of valence electrons same as group number
where are the metals mainly located
left side
what are the elements in group 0
inert or noble gases
have full valence shell
what do other atoms of periodic table want to achieve
full stability by gaining or losing electrons in valence shell
define ion
particle with positive or negative charge where the number of protons and electrons are unequal
which groups lose electrons
1 2 3 to form positive charged ions called cations —- metals
which groups gain electrons
5 6 7 gain an electron and form negatively charged ions called anions —— non metals