Understand Chemistry Bond Symbol for Antioxidants and Free Radicals

[Stephanus]

Dear PF Forum,
I'm trying to understand antioxidant and free radicals. But I'm afraid that my chemistry is weak.
Perhaps someone can help me with this picture?
https://en.wikipedia.org/wiki/Hydrogen_peroxide

This is Hydrogen Peroxide. Neutral.
As much as I can surmise in this picture is...
1. It's H₂O₂, I don't need the picture to guess H2O2, Hydrogen Peroxide is clear.
2. Oxygen (Z = 8, electron configuration: 1s² 2s² 2s⁴ , Oxygen lacks 2 electrons in its outer shell.
3. Hydrogen (Z = 1, 1s¹ ), lacks 1 electron
4. Left Oxygen is bound to upper left Hydrogen and right Oxygen, making it complete.
5. So is Right Oxygen.
6. Upper left Hydrogen is bound to left Oxygen, making it complete
7. So is Right Hydrogen.

What I want to ask is that symbol
A: Triangle
B: Broken triangle
C: Rectangle
Why A, B and C pictures are different? Are they bonded in different ways?

Thanks for any help.

 

[DrClaude]

A and B are common 2D representations of 3D structures. A is for a bond that is partially sticking out of the page, and B for a bond that is partially back of the page. C is for a bond that is in the plane of the page.

See, e.g., http://www.chemeddl.org/resources/stereochem/threed3.htm or https://en.wikipedia.org/wiki/Skeletal_formula#Stereochemistry

 

[Stephanus]

Thanks Dr. Claude. I understand.

 

[DrClaude]

I should add that in the case of H₂O₂, this illustrates that the molecule is not planar. The dihedral angle is 120°.

 

[Stephanus]

Thanks.
One more thing. Do you think that B - bond should be upside down? If you know what I mean I just click your link. No, it's the right picture. The broken triangle (B) should be as in the original picture, not upside down. Both hydrogens are 'close' to us. If we can say that.
I'm trying to edit the picture but your second reply just comes up.
And if H2O is three atom, that makes it planar, 2D
Then this Hydrogen peroxide perhaps is 3D?

Now, I think I can move on a little
Thanks DrClaude

 

[DrClaude]

Both hydrogens are 'close' to us. If we can say that.

Not sure what you mean here, but one hydrogen is closer to us than the oxygens, and one is farther away.

And if H2O is three atom, that makes it planar, 2D

Yes, with 3 atoms, you can always define a plane, except for linear molecules.

Then this Hydrogen peroxide perhaps is 3D?

All the atoms aren't in one plane, which is why you need the wedges to draw it in 2D.

 

[Stephanus]

Not sure what you mean here, but one hydrogen is closer to us than the oxygens, and one is farther away.

Yes, yes. I understand. All this time, I've never taken a glance at chemistry. I've never realized the molecule could be cubed or perhaps tetrahedron (dodecahedron??). Should have taken just 5 minutes to ponder it myself to realize it.

Yes, with 3 atoms, you can always define a plane, except for linear molecules.

Yes! Mathematic principle?

All the atoms aren't in one plane, which is why you need the wedges to draw it in 2D.

Ok.
Thank you very much DrClaude

 

[DrClaude]

Yes! Mathematic principle?

Yes. Three non-colinear points define a plane.