Steps for Drawing Atoms 1.Find the element on the periodic table. How many protons does it have? 2. Because atoms are neutral, the number of electrons will equal the number of protons 3. Write the number of protons in the center. 4. Colour in the electrons. Start with the two closest to the nucleus and work outwards.

Drawing Atoms The first ring around the nucleus can hold a maximum of 2 electrons. The second ring around the nucleus can hold a maximum of 8 electrons. The third ring can around the nucleus can hold a maximum of 8 electrons. The fourth ring around the nucleus can hold a maximum of 18 electrons.

Electron Shells for the First 20 Elements

Making Ions The goal of every element is to have a full outer shell. Electrons are gained or lost in order to attain a complete outer shell.

Making Negative Ions Chlorine has 17 electrons. Seven of those electrons are in the outer shell. In order for Chlorine to have a complete out shell it has to gain one electron or lose seven electrons. It will gain one electron.

Making Positive Ions Sodium has 11 electrons. One of those electrons is in the outer shell. In order for sodium to have a complete outer shell it would have to gain seven electrons or lose one electron. It loses one electron.

Valence Electron Trends Elements in the Alkali Metal Family (H, Li, Na, K, Rb, Cs, and Fr) tend to lose 1 electron. Elements in the Alkaline Earth Metal Family (Be, Mg, Ca, Sr, Ba, and Ra) tend to lose 2 electrons. Elements in the Boron Family (B, Al, Ga, In, and Ti) tend to lose 3 electrons.

Valence Electron Trends Elements in the Carbon Family (C, Si, Ge, Sn, Pb) can gain or lose 4 electrons. Elements in the Nitrogen Family (N, P, As, Sb, Bi) tend to gain 3 electrons. Elements in the Oxygen Family (O, S, Se, Te, Po) tend to gain 2 electrons. Elements in the Halogen Family (F, Cl, Br, I, At) tend to gain 1 electron. Elements in the Noble Gas Family (He, Ne, Ar, Kr, Xe, Rn) do not tend to gain or lose electrons as their outer shells are already complete.

How to Draw Electron Dot Diagrams Imagine a square around the element symbol. Determine the number of valence electrons. –Alkali Metals have 1 –Alkaline Earth Metals have 2 –Boron Family has 3 –Carbon Family has 4 –Nitrogen Family has 5 –Oxygen Family has 6 –Halogen Family has 7 –Noble Gas Family has 8

More on How to Draw Electron Dot Diagrams When filling the sides with electrons, each side gets one electron before any side gets two. Start at the top and work clockwise around the box. Once each side of the box has two electrons, the shell is full. Beryllium Be Boron B Silicon Si Nitrogen N

Forming Ions In an atom the number of protons equals the number of electrons. If electrons are added to an atom, the atom now has more negatives than positives. It has a negative charge. This is an anion. If electrons are removed from an atom, the atom now has more positives than negatives. It has a positive charge. This is a cation.

Naming Ions To name a Cation (positively charged ion), write the element name followed by the word ion. Mg +2 is called Magnesium Ion To name an Anion (negatively charged ion), write the name of the element and change the ending to “ide” S -2 is called Sulfide

Writing Ionic Symbols From Names When given the name of an ion and the ending does not have “ide”, then you know this is a positive ion. Write the element’s symbol with a positive charge (recall the valence electron trends to know what the charge is). The symbol for Potassium Ion is K +1 When given the name of an ion that ends in “ide”, you know it is a negative ion. Write the element’s symbol with a negative charge (recall the valence electron trend to know what the charge is). The symbol for Nitride is N -3

Transition Metals The elements in columns 3 to 12 are called the Transition Metals. Transition Metals are always positive. To know what the charge is you will have to look at the Roman Numeral in the name. Iron (III) means Fe +3 Nickel (II) means Ni +2

Traditional and Stock System Names of Transition Metals You will be given a table of traditional names for transition metals. Some examples of traditional names are Ferrous (Fe +2 ) and Ferric (Fe +3 ). The system we mostly use in this class is the Stock System. In the Stock System, Fe +2 would be Iron (II) and Fe +3 would be Iron (III).