Chemistry

1. 6. Ionic compounds

1.1. Ionic compounds only form between a metal and a non-metal. Ions that have opposite charges attract each other. The opposite negative and positive charges of the ions hold together in ionic bonds, forming ionic compounds, which are compounds made of ions. The loss or gain from one atom matches the loss or gain of the other, so one atom essentially 'donates' an electron to the other atom it pairs up with. Ionic solid's oppositely charged ions are arranged in a regular way to form giant ionic lattices.

2. 7. Naming rules for ionic compouds

2.1. The chemical name indicates the elements present in the compound. The rules for naming ionic compounds are: the positive ion is always the first part of the name, the negative ion is always the second part of the name and the non-metal ion's (negative ion) name ends with the suffix "-ide".

2.2. For example, Calcium and Nitrogen change to calcium nitride.

3. 8. Naming rules for polyatomic compounds

3.1. Polatomic ions form ionic compounds and follow the same rules as regular ionic compounds (#7).

4. 9. Naming rules for multivalent compounds

4.1. To name multivalent compounds follow these steps: 1. Write the full name of the metal first. 2. Reverse the criss cross (uncross the subscripts to determine the charges). 3. Check the non metals combing capacity (non metals have only one combing capacity). If its not correct, the formula needs to be reduced. 4. If there are multiple possible combining capacities for the metal, write a roman numeral. Roman numerals are only used for metals. 6. Write the name of the non-metal, drop the ending and add "-ide".

5. 10. Naming rules for covalent compounds

5.1. To name most of the covalent compounds follow these rules: 1. Determine how many times the first atom appears in the molecule. Write the Greek prefix for this number. If its only 1 you don't need a prefix. 2. Write the full name of the first element in the compound. 3. Determine how many times the second atom appears in the molecule. This is the number written in subscript next to it in the molecular formula. Write the Greek prefix for this number of the second atom. 4. Name the second atom and end it with "-ide."

6. 1. How to calculate protons, neutrons and electrons

6.1. To calculate the number of protons in an atom all you have to do is look at the atomic number. Atomic number = number of protons.

6.2. To calculate the number of neutrons in an atom you have to minus the number of protons (atomic number) from the average atomic mass. Atomic mass - atomic number = number of neutrons.

6.3. To calculate the number of electrons in a neutral atom all you have to do is look at the atomic number. Atomic number = number of electrons. But in an ion (charged atom) you add or minus the electron count from the atomic number. If the electron count was +3 then you would minus 3 from the atomic number. If it was -3 then you would add 3 to the atomic number to get the number of electrons.

7. 2. Atomic mass

7.1. The atomic mass number is the total number of protons and neutrons in the nucleus of an atom. Its the mass of the average atom of that type.

8. 3. Atomic number

8.1. The atomic number is different for every element and is what gives the element its identity. The atomic number is the number of protons in the nucleus of an atom.

9. 4. How charge affects atoms

9.1. Atoms that become charged are called ions. They become charged when electrons are added or removed. A filled valence shell (the outermost occupied shell) gives the atom stability. Atoms with filled valence shells are very unreactive and do not easily trade or share electrons, while other atoms will gain or lose electrons in order to achieve stability.

10. 5. Covalent compound

10.1. Covalent compounds are made up of more than one kind of atom that share electrons to form molecules, resulting in an electrically neutral molecule.