When i was learning about how many elements ?

Question

where in a atom i learnt by like circles with in circles with the elements on each circle(shells) but when i went on to learn about it futher i was shown a circle with like ovals connected to the circle with the elemts in the oval and i do not understand what the deal with the ovals and that is, this is as best as i can discribe this if anyone can help with it would be great

Answer 1

It sounds like you're talking about VSEPR models: http://en.wikipedia.org/wiki/Image:AX4E2...

If that's what you're thinking, the ovals that extend from the balls are lone electron pairs (most people don't draw them on).

Answer 2

Do you mean learning about how many electrons are in an atom?

If so, maybe in the earlier courses they drew it like planets orbiting a sun to keep it simple, but that model does not adequately explain the observed bonding and other behavior very well. They have refined that model and found that some electrons behave as if the were in a spherical orbit and some behave as if they were in "oval" or, more exactly, "dumbbell-shaped" orbits. Also different orbitals can hybridize and generate new shapes which better explains the observed bonding configurations. Keep in mind the orbital shapes represent the place where the electron has the highest probability of being, and that nobody has seen these electrons whizzing around or seen the orbitals directly. It is just a tool to explain observed behavior. You should probably look through a good P-chem book to get further briefing on this.

Answer 3

When people first learn about atoms they learn that the electrons orbit the nucleus in concentric circles. The next stage is to do a better model, some go in circles, and some go in in these ovals above and below the nucleus. You can never really say where all the electrons are, but the circles and ovals drawn mean they are usually inside these areas. The more you study it the more complicated the pictures get!