atoms and ions2

Atoms and Ions

TSRS M/Ena Gaur/2016-17

The Shri Ram School

Moulsari Campus

Atoms are electrically neutral!

It means, in an atom-

Number of Protons (+) = number of electrons (-)

Total Positive charge = total negative charge


TIP to remember charge

on particles:

P for Protons,

P for Positive/Plus charge

Atoms become Ions.. In a reaction, when atoms combine, they lose

their neutral nature and become positive or

negative to become more stable.

When an atom has more of electrons, it will have

more – charge. This means less protons or +

charge.

OR

When an atom has more of protons, it will have

more + charge resulting in less number of

electrons or – charge.

This imbalance results in a

charged atom called ION.

Less protons

(+ charge )

More electrons (- charge )


CATIONS

If an atom LOSES 1 electron, it means:

o The atom has 1 proton more than the electrons, resulting

in more + charge.

o Thus the atom is now positively charged and is called a

CATION.


ANIONS

If an atom GAINS 1 electron, it means:

o The atom has 1 electron more than the protons, resulting

in more - charge.

o Thus the atom is now negatively charged and is called an

ANION.


TIP to remember Cations and Anions!


Remember…

An excess of electrons gives a negative (-)

charge making the atom an ANION.

An excess of protons gives a positive (+)

charge making the atom a CATION.


For example….


Revise and practice Exercise 2 from your

textbook (Page 7) and complete the

table to test your learning.


atoms and ions2

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