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Ions are formed when an element loses or gains one or more electrons.
Combining capacity is how many electrons are gained or lost from an element. You have to use the periodic table to find the combining capacity of elements.
Ions 'steal' electrons from each other to form compounds, meaning that one takes a certain number of electrons from the other so that both ions have a full outer electron shell.
An anion is an ion with a negative charge, such as fluorine. This element tends to gain one electron so it would have a full outer electron shell. After it gains an electron, the element fluorine becomes an anion- F-1.
A cation is an ion with a positive charge, such as calcium. Calcium tends to lose two electrons so it would have a full outer electron shell. This cation is Ca+2.
However, polyatomic ions attract opposite charged ions.
A polyatomic ion is one ion that is made up of more than one atom, such as ammonium (NH4+1). This polyatomic ion is made up of one nitrogen atom and four hydrogen atoms, and is a cation which has lost one electron.
An ionic compound forms when positive ions bond with negative ions, such as sodium chloride (NaCl). Since sodium is a positive ion and chlorine is a negative ion, they can bond to form sodium chloride, or table salt.
Ions, Ionic Bonding, and Ionic Compounds
There are two ways of determining formulas of ionic compounds- the cross method and the balancing method.
Here is an easier example (cross method): Li+1 and O-2; switch the numbers 1 and 2 so you'd get Li2 and O1. The final result is Li2O.
An example of the balancing method: LI+1 and O-2. This isn't stable since +1 -2 is -1 (when ionic compounds form, they should form neutral compounds). So you have to place another lithium atom so you'd get Li2+1. That way, you'll get a neutral ionic compound. So since we used two lithium atoms and one oxygen atom to balance the ionic compound, our final result would be Li2O.
You can determine names for ionic compounds by saying the name of the element of the cation, and then saying the name of the element of the anion, but saying 'ide' in the end. So if you wrote down KCl, you wouldn't say potassium chlorine, but you'd say potassium chloride.
Only metals and nonmetals can combine to form ionic compounds, since they attract each other.
You can determine names for ionic compounds that have roman numerals. For example, FeS would be said as iron (II) sulfide, since Fe+2 would be written as Fe (II). Fe (II) can also be said as ferrous, so FeS can also be said as ferrous sulphide.
This is a photo of table salt (NaCl), which is an edible ionic compound. Source: http://img.alibaba.com/photo/104369216/Low_Sodium_Salt_Salt_Substitute_Table_Salt.jpg
This picture is potassium nitrate, which is another ionic compound. Source: http://images.asia.ru/img/alibaba/photo/50873948/Potassium_Nitrate.jpg
By: Hassan Hassan
Questions: 1. What is a cation? 2. What is an anion? 3. How are ions formed? 4. What is combining capacity? 5. How do ions form compounds? 6. What is a polyatomic ion? 7. What are two ways of determining formulas for ionic compounds? 8. How do you determine names for ionic compounds?
Answers: 1. A cation is an ion with a positive charge. 2. An anion is an ion with a negative charge. 3. Ions are formed when an element loses or gains one or more electrons. 4. Combining capacity is how many electrons are gained or lost from an element. 5. Ionic compounds are formed when positive ions bond with negative ions. 6. A polyatomic ion is one ion that is made up of more than one atom. 7. Two ways of determining formulas for ionic compounds are the cross method and the balancing method. 8. You can determine names for ionic compounds by saying the name of the element of the cation, and then saying the name of the element of the anion, but saying 'ide' in the end.