Chemistry Unit 3

It was developed by Dimitri Mendeleev who organised elements bades on increasing molar mass and similar properties, not by atomic number. 

The properties of elemtns repeat in pattern on the periodic table when they are organized by increasing atomic mass.

horizontal row on periodic table. Elements in a period have the same number of shells (energy levels).

vertical columns on peridoic table. Elements within a group have similar properties, numbers on top of the periodic table indicate the group #.

the eight "tallest" columns on the periodic table, groups 1,2 & 13-18

groups 3-12, have greater complexity in electron configuration, many of these can form more than one type of ion

- hight melting points (all execpt mercury are solid at room temperature)

- shiny when freshly cut or polished

- malleable (dehnbar) -> can pushed into a sheet

- ductile (plastisch verformbar) -> can be pulled into thin water 

- generally flexible as thin sheets or wires

- good conductors of heat and elctricity

- tend to lose electrons and form positive ions when reacting

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- lower melting points

- solids are not malleable, ductile or flexible

- poor conductors of heat and electricity 

- tend to gain electorns and form negative ions when reacting or will share electrons when reacting with other non-metals