Groups and electron dot diagrams

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If you want to see how atoms of one element will react, it is handy to have an easier way to represent the atoms and the electrons in their outer energy levels.

Why do atoms combine?

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You can do this with electron dot diagrams.

An electric dot diagram is the symbol for the element surrounded by as many dots as there are electrons in its outer energy level.

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How to Write Them

The dots are written in pairs on four sides of the element symbol.

Why do atoms combine?

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Start by writing one dot on the top of the element symbol, then work your way around adding dots to the right, bottom, and left.

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How to Write Them

Why do atoms combine?

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Add a fifth dot to the top to make a pair. Continue in this manner until you reach eight dots to complete the level.

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Using Dot Diagrams

Now that you know how to write electron dot diagrams for elements, you can use them to show how atoms bond with each other.

Why do atoms combine?

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A chemical bond is the force that holds two atoms together.

Atoms bond with other atoms in such a way that each atom becomes more stable. That is, their outer energy levels will resemble those of the noble gases.

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Section Check

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Question 1

Electrons are now known to swarm around the nucleus of an atom in a configuration known as the _.

A. electron circle

B. electron cloud

C. electron configuration

D. electron swarm

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Section Check

Answer

The answer is B. The “cloud” includes all the regions where an electron might be found.

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Section Check

Question 2

What information can you learn from this diagram?

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Section Check

Answer

This image is an example of an electron dot diagram. It tells you that nitrogen contains five electrons in its outer energy level.

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Section Check

Question 3

The _ an energy level is from the nucleus, the _ electrons it can hold.

A. closer, more

B. closer, less

C. farther, less

D. farther, more

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Section Check

Answer