Question 1
A π (pi) bond is the result of the:
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overlap of two s orbitals.◦
overlap of an s orbital and a p orbital.◦
overlap of two p orbitals along their axes.◦
sidewise overlap of two parallel p orbitals.◦
sidewise overlap of two s orbitals.Question 2
According to the VSEPR model, the arrangement of electron pairs around NH3 and CH4 is:
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different, because in each case there are a different number of atoms around the central atom◦
different, because in each case there are a different number of electron pairs around the central atom◦
the same, because both nitrogen and carbon are both in the second period◦
the same, because in each case there are the same number of electron pairs around the central atom◦
different or the same, depending on the conditions leading to maximum repulsion
Electron Microscope Images of a Diatom
Human Heart Model
Eye Model
The 31 pairs of spinal nerves.
A model for the operation of voltage-gated sodium channels.
The operon model, as proposed in 1961 by Jacob and Monod