The Power of the Periodic Table

The Periodic Table

Dmitri Mendeleev ( )

Metals, nonmetals, metalloids

Metallic elements are solids at room temperature (except mercury)

Shiny, bendable

Good conductors of heat and electricity

Most elements are metals

Metals

Non-Metals

Most are gases at SATP (SATP = Standard ambient temperature and pressure = 25 o C, 100kPa)

Not shiny or bendable fluorine

Generally NOT good conductors of heat and electricity

Carbon Hard Soft

Sulfur Essential for life: component of all proteins, enzymes and…..

Curly Hair

Metalloids (semi-metals) These elements lie on a diagonal line (staircase) between the metals and non- metals

Metalloids’ chemical and physical properties are intermediate between metals and nonmetals

Metalloids

Elements are arranged: Vertically into Groups Horizontally Into Periods

How many groups are there? How many periods are there?

Each group has distinct properties

Why?

If you looked at the atoms of every element in a group you would see…

Each atom has the same number of electrons in its outermost shell. An example…

The group 2 atoms all have 2 electrons in their outer shells Be (Beryllium) Atom Mg (Magnesium) Atom

The number of outer or “valence” electrons in an atom affects the way an atom bonds. The way an atom bonds determines many properties of the element.

This is why elements within a group usually have similar properties. This is called the Periodic Law – if you group the elements according to atomic number they will fall into groups of similar properties

The Power of the Periodic Table

If you looked at an atom from each element in a period you would see…

Each atom has the same number of electron shells. An example…

The period 4 atoms each have 4 electron containing shells K (Potassium) Atom Fe (Iron) Atom Kr (Krypton) Atom 4 th Shell

The Power of the Periodic Table

Four chemical families of the periodic table: the alkali metals (IA), the alkaline earth metals (IIA), halogens (VII), and the noble gases (VIIIA).

Alkali Metals

Group 1: Alkali Metals Cutting sodium metal Reaction of potassium + H 2 O

Soft, silvery coloured metals Very reactive!!! edu/webdata/U sers/DMcDowel l/GenChem/alka lishow.html

Alkali Metals react with water to form alkaline (basic) solutions: Li (Lithium) – least reactive Li (Lithium) Na (Sodium) K (Potassium) Rb (Rubidium) Cs (Cesium) – more reactive Cs (Cesium)– What would you expect from Francium?!?!

Group 2: Alkaline Earth Metals

Magnesium Magnesium oxide Group 2: Alkaline Earth Metals

Silvery-White Metals Fairly reactive Many are found in rocks in the earth’s crust

Transition Metals

Malleable (easily bent/hammered into wires or sheets) Most are good conductors of electricity

How many things can you think of that have Transition Metals in them?

Metalloids lie on either side of the “staircase”

They share properties with both metals and non- metals Si (Silicon) and Ge (Germanium) are very important “semi- conductors”

What are semiconductors used in?

NONMETALS To the right of the metalloids Brittle Do not conduct electricity

Group 17: The Halogens iodine

Most are poisonous Fairly reactive because only need one electron to gain stable outer energy level (8e - ) – so react with alkali metals Na + and Cl -  NaCl Halogens

Xylyl bromide, chlorine gas, and the chlorine containing mustard gas and phosgene have been used as chemical warfare agents.

Chlorine Gas The Germans were the first to use Chlorine gas at Ypres in 1915 Chlorine gas is a lung irritant The symptoms of gas poisoning are bright red lips, and a blue face People affected die a slow death by suffocation Decades later men who thought they had survived the war died from lung diseases such as Emphysema

CHLORINE

Unreactive Gases at room temperature Noble Gases

Colors Noble Gases produce in lamp tubes: Ne (Neon): orange-red Hg (Mercury): light blue Ar (Argon): pale lavender He (Helium): pale peach Kr (Krypton): pale silver Xe (Xenon): pale, deep blue

Jellyfish lamps made with noble gases artist- Eric EhlenbergerEric Ehlenberger

Lanthanide Series Actinide Series Lanthanides are found naturally, only one is radioactive Actinides are all radioactive, and some have only been made in particle accelerators Their chemistry is very different from the main group elements and the transition metals.