1. Families of the Periodic Table

2. What are the families of the periodic table?
The periodic table is divided into families.
Just like your family shares similar properties, each family of the periodic table shares similar chemical properties.

3. Family Names
The family name assigned to an element is dependent upon the group number they are found in on the table.
Group One – Alkali Metals
Group Two – Alkaline-Earth Metals
Group 3-12 (d-block) – Transition metals
Group 16 – Chalcogens
Group 17 – Halogens
Group 18 – Noble gases

4. Family Names continued
1st row of the f-block (elements with atomic # 58-71) – Lanthanides
2nd row of the f-block (elements with atomic # ) – Actinides

5. Alkali Metals
The metals in group one of the periodic table make up the alkali family.
This includes lithium, sodium, potassium, rubidium, cesium, and francium.

6. But what about hydrogen?
Hydrogen does not belong to the alkali family. Since hydrogen can act both as a metal and a non-metal, he is not assigned a family.

7. Properties of the Alkali Metals
Located in the s-block
All contain a single s electron as the valence or outermost electron.
Li: [He]2s1 Rb: [Kr]5s1
Na: [Ne]3s1 Cs: [Xe]6s1
K: [Ar]4s1 Fr: [Rn]7s1

8. Reactivity of the Alkali Metals
Note that if all of the alkali metals lost their one s electron, they would have a noble gas configuration which is the goal of all elements.
This makes the alkali metals VERY reactive.
In fact, they are so reactive, they are not found in nature in a pure state.
They combine most vigorously with non-metals.

9. More about an Alkali metal’s reactivity
The alkali metals also react very vigorously with water.
Because of their extreme reactivity with moisture in the air, the alkali metals are stored in kerosene.

10. Physical Properties of the Alkali Metals
All are silvery in appearance
Soft enough to cut with a knife
Melt at low temperatures. The melting point temperature gets lower as you move down the table.

11. Alkaline-Earth Metals
Found in group 2 of the periodic table.
This includes beryllium, magnesium, calcium, strontium, barium, and radium.

12. Properties of the Alkaline-Earth Metals
Located in the s block
All contain a pair or 2 s electrons as the valence or outermost electrons.
Be: [He]2s2 Sr: [Kr]5s2
Mg: [Ne]3s2 Ba: [Xe]6s2
Ca: [Ar]4s2 Ra: [Rn]7s2

13. Reactivity of the Alkaline-Earth Metals
Note that if all of the alkaline-earth metals lost their two s electrons, they would have a noble gas configuration.
The alkaline-earth metals are very reactive but not as reactive as the alkali metals.
They are still reactive enough that they do not exist in nature in their pure state.

14. Physical Properties of the Alkaline-Earth Metals
The alkaline-earth metals are harder, denser, and stronger than the alkali metals.
They also have higher melting points.

15. Transition metals
The elements in groups 3-12 or the d-block elements make up the transition metals.
These metals are usually what comes to mind when you think of the word “metal”.

16. Properties of the Transition Metals
These metals have high luster (shiny).
Good conductors of heat and electricity.
They are typically less reactive than the alkali and alkaline earth metals.
Palladium, platinum, and gold are among the least reactive of all elements apart from the noble gases.

17. Halogens These non-metals are found in group 17 of the periodic table.
The halogens include:
Fluorine, chlorine, bromine, iodine, and astatine.

18. Reactivity of the Halogens
The halogens are the most reactive non-metals. Fluorine is the most reactive non-metal.
F: [He]2s22p5
Cl: [Ne]3s23p5
Br: [Ar]4s2 3d10 4p5
I : [Kr]5s2 4d10 5p5
At: [Xe]6s2 5d10 6p5

19. Reactivity of the Halogens
Note that if all the halogens could gain an electron in their p-orbital than they would have a filled p-orbital and have a noble gas configuration.
This makes the halogens very reactive.

20. Physical Properties of the Halogens
Fluorine and chlorine are gases at room temperature.
Bromine is a reddish liquid.
Iodine is a dark purple solid.
Astatine is a man-made element that has only been prepared in very small quantities.

21. Noble gases
The noble gases are found in group 18 of the periodic table.
The noble gases include:
helium, neon, argon, krypton, xenon, and radon.

22. Noble gases
The noble gases are called inert gases because they do not react!
Ne: [He]2s22p6
Ar: [Ne]3s23p6
Kr: [Ar]4s2 3d10 4p6
Xe : [Kr]5s2 4d10 5p6
Rn: [Xe]6s2 5d10 6p6

23. Noble gases
Note that the noble gases have a filled p-orbital possessing 8 electrons in their outermost orbital.
Noble gases do not want to lose or gain any electrons so they do not react.
However, krypton and xenon have been made into a few compounds.

24. The f-block elements
The f-block elements make up the lanthanides and the actinides.
The lanthanides are shiny metals similar in reactivity to the alkaline-earth metals.
The actinides are all radioactive.

25. What does it mean to be radioactive?
All radioactive atoms have extremely large nuclei packed full of protons and neutrons. Energy within the atom escapes in large bursts due to the overwhelming amount of force within the atom. These spurts of energy are radioactive emissions.