No, they do not. However, elements in the same group have the same number of valence electrons.
Elements in the same family (or group) have the same amount of electrons in their outer shell. For Example, all elements in Group 1 have 1 electron in their outer shells.
Group I elements (that is alkali metals)
alkali metals (group 1 elements)
The alkali metals in group 1 react by losing one electron.
The elements in this group are called Alkali Metals.
Atoms of the elements in a group have the same number of electrons in their outer energy shells. This gives the elements similar Chemical Propetries.
The group of elements that have a stable electron configuration are the noble gases.
Elements in the same family (or group) have the same amount of electrons in their outer shell. For Example, all elements in Group 1 have 1 electron in their outer shells.
The elements in Group 1 have one valence electron in their outermost s orbital.
Elements with similar electron configurations are placed in the same group.
Elements in Sodium's Group (Group 1 - Alkali Metals) will have the same amount of electrons in their outer shell (i.e. 1 electron in the outer shell).
electron cloud
The elements of group 1 has 1 valence electron. They lose 1 electron to form cation.
Group I elements (that is alkali metals)
An outer electron shell with only one electron.
It is in Group 17 that you will find the most reactive elements. These elements all lack only one electron from having that "magic" electron configuration of the inert gases. That makes these elements very "hungry" to get that "last electron" so their electron structures become more stable.
The name of the group of elements with two valence electron in each atom is "alkaline earth metals."