1
99:59:59,999 --> 99:59:59,999
What is the shape of a molecule?

2
99:59:59,999 --> 99:59:59,999
Well, a molecule is mostly empty space.

3
99:59:59,999 --> 99:59:59,999
Almost all of its mass is concentrated

4
99:59:59,999 --> 99:59:59,999
in the extremely dense nuclei of its atoms.

5
99:59:59,999 --> 99:59:59,999
And its electrons,

6
99:59:59,999 --> 99:59:59,999
which determine how the atoms

7
99:59:59,999 --> 99:59:59,999
are bonded to each other,

8
99:59:59,999 --> 99:59:59,999
are more like clouds of negative charge

9
99:59:59,999 --> 99:59:59,999
than individual, discrete particles.

10
99:59:59,999 --> 99:59:59,999
So, a molecule doesn't have a shape

11
99:59:59,999 --> 99:59:59,999
in the same way that, for example,

12
99:59:59,999 --> 99:59:59,999
a statue has a shape.

13
99:59:59,999 --> 99:59:59,999
But for every molecule,

14
99:59:59,999 --> 99:59:59,999
there's at least one way

15
99:59:59,999 --> 99:59:59,999
to arrange the nuclei and electrons

16
99:59:59,999 --> 99:59:59,999
so as to maximize the attraction

17
99:59:59,999 --> 99:59:59,999
of opposite charges

18
99:59:59,999 --> 99:59:59,999
and minimize the repulsion

19
99:59:59,999 --> 99:59:59,999
of like charges.

20
99:59:59,999 --> 99:59:59,999
Now, let's assume that the only electrons

21
99:59:59,999 --> 99:59:59,999
that matter to a molecule's shape

22
99:59:59,999 --> 99:59:59,999
are the outermost ones from each participating atom.

23
99:59:59,999 --> 99:59:59,999
And let's also assume

24
99:59:59,999 --> 99:59:59,999
that the electron clouds in between atoms,

25
99:59:59,999 --> 99:59:59,999
in other words, a molecule's bonds,

26
99:59:59,999 --> 99:59:59,999
are shaped kind of like sausages.

27
99:59:59,999 --> 99:59:59,999
Remember that nuclei are positively charged

28
99:59:59,999 --> 99:59:59,999
and electrons are negatively charged,

29
99:59:59,999 --> 99:59:59,999
and if all of the molecule's nuclei

30
99:59:59,999 --> 99:59:59,999
were bunched up together

31
99:59:59,999 --> 99:59:59,999
or if all of its electrons were bunched up together,

32
99:59:59,999 --> 99:59:59,999
they would just repel each other and fly apart,

33
99:59:59,999 --> 99:59:59,999
and that doesn't help anyone.