To explain the difference between elements and compounds, a teacher filled clear boxes with balls.
Which box best represents a sample of an element?

A

Explanation:

An element is a substance, made up of atoms of the same substance and has independent existence. An element cannot be broken up by physical or chemical processes.

If we look at the images closely, image A represents a substance made up of the same kind of atoms. All the balls are exactly of the same colour and type, hence the answer.

electron microscopy and scanning tunneling microscopes gives us a greater understanding of atoms by being able to see the atom itself, and lets us see some atomic reactions.

explanation:

consider the reaction below.

 no rx

at 500 k, the reaction is at equilibrium with the following concentrations.

[pci5]= 0.0095 m

[pci3] = 0.020

[ci2] = 0.020 m

what is the equilibrium constant for the given reaction?

0.042

0.42

2.4

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