Elements: are pure substances that cannot be broken down into simpler substances.
Periodic Table of the Elements: is a useful tool that chemists use to explain and predict the properties of the elements
on it!
Where are the following on the periodic table: Metals, non-metals, metalloids, groups, periods, halogens, alkaline earth
metals, noble gases, alkali metals?
How are the elements arranged on the periodic table?
What do the letters and numbers in each box represent?
Why are some elements coloured blue, black or red?
Atomic Structure
Matter is anything that has mass and takes up space but what is it made up of?
An atom is made up of subatomic particles, what are they? Where are they found within the atom? Any charges?
Electrical Charge
Symbol
Location
Bohr-Rutherford diagrams: useful tool to show the arrangement of electrons around the nucleus of the first twenty
elements.
Electrons occupy regions of space outside the nucleus called energy levels or shells. Each shell dictates how many
electrons can be found there.
 First shell holds a max of 2 electrons

second shell holds a max of 8

third shell holds a max of 8 electrons

the outermost energy shell is called the ____________ shell.
Trick to drawing Bohr-Rutherford diagrams:
1. The number of total rings (representing energy shells) is equal to the period number the element is in. Elements
in the same period have the same number of rings.
2. The total number of electrons drawn is equal to the atomic number of that atom (only for a neutral atom not an
ion).
3. The number of valence electrons for a neutral atom is equal to its group number (1, and 2). For groups 13-18,
drop the 1. Exclude the transition metals.

All elements of the same group have the same number of valence electrons and have similar chemical
properties!
The goal in chemistry is stability! Those valence electrons matter!
All elements on the periodic table, except for the noble gases, are unstable! They are very reactive and want to settle
down (stabilize). The goal of all elements is to become stable. The way in which they become stable is by gaining a full
valence shell. All elements want this. The only way they can get a full valence shell is by chemically reacting with other
elements that are unstable (A compound is formed!). When a chemical reaction takes place it is only the valence
electrons that are reacting with each other. We see this as a colour change, light, heat, bubbles, precipitate etc. How do
they gain a full valence shell? Yes they are chemically reacting with another element, but what is actually happening is
they are either giving away, taking in or sharing valence electrons with another unstable atom!!