Wize High School Grade 12 Chemistry Textbook > Atomic Models and Properties of Atoms
The Periodic Table & Properties
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The Periodic Table of Elements
The periodic table is something we are going to see a lot of in chemistry! It organizes the elements by their atomic number (Z) and is organized into groups (columns) and periods (rows).
Elements in the same group have very similar reactivity which we will talk about more when we learn about things like valence electrons, bonding, and Lewis structures.
You should be familiar with each of the following labels:
- Groups
- Periods
- Alkali Metals
- Alkaline Earth Metals
- Transition Metals
- Nitrogen group (aka Pnictogens)
- Oxygen group (aka Chalcogens)
- Halogens
- Noble (Inert) Gases
- Metals
- Non-metals
- Metalloids
- Lanthanides and Actinides (aka Rare Earth Metals)
Practice: Understanding Noble Gases
Which of the following statements is true?
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Periodic Groups
**Just read over for a general understanding :)
Metals
- reactive (group 1 and 2) are more reactive than transition metals
- solid except for Hg and on warm days, Ga
- ductile, malleable
Non-metals
- solids, liquids (Br), gases (H, He, O2, F2, Cl2)
- don't conduct electricity (insulators) except for C (graphite)
- ones on the right of the periodic table are more reactive (closer to having a full octet so willing to react more to get it)
Alkali Metals (Group 1)
- very reactive (and love to react with halogens since the alkali metals want to lose 1 electron and the halogens want to gain 1 electron to have a full octet of 8 electrons)
- only found in nature bound to other elements (ex. NaCl)
- silvery and soft
- all react with water, more violent reactions as you go down a group, producing a basic solution
Alkaline Earth Metals (Group 2)
- silvery and soft
- all react with water, except Be which only reacts with steam
- slowly oxidized in air, except Be and Mg
Transition Metals
- hard
- not as reactive as other metals
- only gold, silver, and platinum can be found in pure element form in nature
Halogens
- all exist as diatomic molecules (ex. not Cl but Cl2)
- Cl2-yellow gas
- F2-green gas
- Br2-brown, volatile, liquid
- I2-black volatile solid, purple vapour
- all very reactive, particularly with alkali metals (alkali metals are looking to lose an electron, while halogens want to gain one electron)
Lanthanides
- the 2nd last period in the periodic table (often in a separate box below transition metals)
- very similar physical + chemical properties; hard to separate one from the others
Actinides
- the very last period in the periodic table
- all radioactive (speaking of radioactivity, the other elements in the periodic table that are radioactive are: Francium, Radium, Astatine)