SNC2D1
Date:__________________
Name:_____________________
L4: 5.5 Reactivity: Atoms and Ions
Atoms are electrically _______ particles. Thus, number of protons = number of electrons. (#p+ = #e-)
For example a Magnesium atom (Mg) has 12 protons and 12 electrons. ________________________
Ions are atoms that have an electrical _______ due to a _____ or _____ of electrons. Thus, #p+ ____ #e-.
For example, a Magnesium ion (Mg2+) loses 2 electrons so it has 12 protons and 10 electrons. _____________________
Why does this occur? Watch this for 2 minutes: http://study.com/academy/lesson/ions-predicting-formation-charge-and-formulas-of-ions.html
 The goal of every atom is to have a ______ valence (outermost) shell to be stable. This is called the _______________
 In order to obtain a full valence shell, atoms ______ with other atoms  forming ____________ .
 During these chemical reactions some atoms ______ electrons in their valence shell and some ______ electrons.
 The _____________ of an element depends on the __________________________.
https://www.youtube.com/watch?v=900dXBWgx3Y
For example, Na has 1 valence electron. It wants to have the outermost shell full.
It either has to lose 1 electron so that its valence shell is now the 2nd orbit (which is full with 8 electrons) or it has to gain 7
electrons to fill the 3rd shell. Which do you think is easier? What will be the net charge on the ion? Show this in the symbol.
What about oxygen? How many valence electrons does it have? Will it lose or gain electrons? How many of them? What will the
net charge be? Draw the BR for the ion and write the ion symbol (showing the charge).
Atoms can do any of the following to obtain a full outer shell:
1. _______ electrons (give electron to another atom)
2. _______ electrons (take electron from another atom)
3. _______ electrons
Losing and gaining electrons will give the atom an ____________________. Any element that does NOT have the same number of
protons and electrons is called an _______. This means it has an overall ______________.
But the ion is more stable than the original atom, because it has reached its goal of a full valence shell.
Note: the electrons that are lost, shared, or gained are the ones furthest from the nucleus the ___________________.
Question 1: Draw the BR diagrams for the sodium ion, fluoride ion and the neon atom. Write their symbols (which must include
the ionic charge). What is similar for all three? What is different?
Two or more atoms and/ or ions are ________________ if they have the same number of electrons and the same electron structure.
SNC2D1
The Lewis Structure of an Ion differs from the atom as follows:
 Electrons are either added or removed from the original Lewis structure of the atom
 Square brackets are drawn around the symbol and a superscript indicating the net charge of the ION is
written on the top right side of the bracket. For example, the oxygen ion is shown as:
Question 2: Draw the Lewis Structure for the fluorine atom and the fluoride ion.
REACTIVITY OF METALS AND NON METALS:
 Metals with 1,2 or 3 valence electrons tend to _______ electrons producing _______ ions called _______.
 Non Metals with 5, 6 or 7 valence electrons tend to _______ electrons producing _______ ions called _______.
 Elements within the _______________ on the periodic table form ions that all have __________________ charge.
 As you go down a metal group, the reactivity ____________. This is because the number of shells increases so the valence
electrons are ___________________________________________________________________
Watch the following ASAP Science video of Alkali metals reacting with water (including francium clips).
http://www.bing.com/videos/search?q=alkali+metal+reaction+video+brainiacs&FORM=VIRE1#view=detail&mid=127152FCC822C3BA257D127152FCC822C3BA257D
Look at the BR worksheet that you filled out. What will the ionic charge be for the ions formed from group 1? group 2? group15?
group16? group 17? group18?
Note: Hydrogen is special. It can gain or lose an electron to be stable. (Usually it loses an electron).
NAMING IONS:
The name of a cation stays the _______ as the element name. For example, sodium forms sodium Ions.
The name of an anion is different from the element name. The anion name has “_____” connected to the stem of the name.
For example:
oxygen forms ________________
Flourine forms ________________
Below is a list of some common anions with their name and symbols:
Element Name
Hydrogen
Fluorine
Chlorine
Bromine
Iodine
Oxygen
Sulphur
Nitrogen
Phosphorus
Anion Name
Anion Symbol
Homework: Read Section 5.5, complete p.191 #1-9; LDS Worksheet; Ions worksheet; study for quiz