Why do all elements in a group have similar physical and chemical properties?

Answer 1

Seldom do they have similar physical properties - many of those depend on Atomic Mass and related properties, and they increase down the group. Chemically, they are similar mostly because their outer (valence) electronic structure is the same.

Answer 2

Electrons in the same group on the Periodic Table require the same number of electrons to fill their valence shells. Because of this, as you move down the group (column), all electrons will have the same number of valence electrons.
Because they have similar electron configurations

ex: the nobel gasses always have 8 valence electrons on their outer shells and, thus, have similar chemical properties

Answer 3

Elements of the same group have similar physical and chemical properties since they have the same number of atoms in the outer most level. As such, they have the same type and strength of bond holding such atoms.

Answer 4

Elements in the same group of the periodic table have similar properties because their electronic configurations have the same number of electrons in the outermost shell. Elemental behavior is almost completely reliant on this outermost shell configuration, with inner shells playing a less important role in determining properties.

Answer 5

Because they have the same number of valence electrons

Answer 6

because the particles are equal amounts in each element

Answer 7

Because an element can either be added to something and the chemical change can happen when you changethe element all toghether.

Answer 8

The properties of an element are determined by their electronic arrangement (the electrons in their different sub-shells). They are similar enough in each group to have similar properties.

Answer 9

Elements in the same group have the same number of valence electrons, which determines their reactivity and bonding behavior. This results in similar physical and chemical properties within a group.