Key idea
Ions
An ion is an atom or molecular entity carrying a net electric charge because its numbers of protons and electrons are not balanced.
Ions
The key idea
An ion is an atom or molecular entity carrying a net electric charge because its numbers of protons and electrons are not balanced.
Why it matters
Losing electrons gives a positive charge; gaining electrons gives a negative charge. This simple bookkeeping is behind salts, electrochemistry and much of solution chemistry.
A picture to remember
Key idea
Ions
+
Guided example
Ions
An ion is an atom or molecular entity carrying a net electric charge because its numbers of protons and electrons are not balanced.
Put it into practice
Ions
Choose a concrete case linked to Ions. Write down the known information, what you are trying to find, and the units. Then state the rule, model or trend you will use. If a calculation is involved, keep the units visible at every line; if it is conceptual, state what changes and what remains fixed.
Check your answer
A strong answer contains four things: the starting situation, the variable that changes, the direction or numerical result, and one check. The check can be a unit, an order of magnitude, a limiting case or a comparison with a familiar example.