Why are the properties of elements periodic?

Question

anonymous · Answer

Electron configurations! Their electron shell configurations are similar, giving them similar reactivities. For example... the noble gases aren't very reactive because they already have a full octet. They're plenty happy without having to form any bonds.

anonymous · Answer

Thaks, can you help me with another question?

anonymous · Answer

Sure :)

anonymous · Answer

How do the electron configurations differ as you move down group 1?

anonymous · Answer

The last electron put in to each of the group 1 elements is an "X"s^1 electron. It could be 1s^1, 2s^1, 3s^1, and so on, depending on the period it is in. So the key difference is that the valence electrons are increasing in distance from the nucleus.

anonymous · Answer

Whenever they increase do they increase by one number?

anonymous · Answer

The number of electrons overall doesn't increase by one number, no. The "Principle Quantum Number" that indicates the energy level that the electron is in, does increase by one number though.

anonymous · Answer

Ohh ok i was sooo confused lol

anonymous · Answer

Hope it's a little more clear now! :D

anonymous · Answer

it is thank you

anonymous · Answer

:P