SPM Form 4 Chemistry Notes — Chapter 4『4.1』The Periodic Table of Elements

Erm... 因为Periodic Table的历史来源很少会出题，所以我就Skip掉了，哈哈哈哈~~:P 但是还是鼓励大家去读一读比较好，因为有可能在Objective出现~ :D 只要refer各自的Chemistry课本都会有了哦！

Periodic Table

Groups and Periods in the Periodic Table

1) Each vertical column is called a group.

   a. There are 18 groups.

   b. Elements with similar chemical characteristics are grouped together.

   c. Each group contains elements with same number of valence electrons.

2) Each horizontal row is called a period.

   a. There are 7 periods.

   b. Each period contains elements with same number of shells which are filled with electrons.

   c. Each period contains elements with chemical and physical characteristics which change progressively from metal to non-metal.

d. Elements are arranged according to the order of their proton number which increases horizontally.

Group	Name of group
Group 1	Alkali metals
Group 2	Alkaline earth metals
Group 17	Halogens
Group 18	Noble gases
Group 3 to 12	Transition elements

Group 1 - very reactive metals

Group 18 - highly unreactive noble gases （chemically inert）

All transition elements - have metal characteristics.