Introduction to Hydrogen and the Alkali Metals

1. OUR OBJECTIVE
• WE will begin learning the groups of Mendeleev’s Periodic Table. Today’s lesson
focuses on the Alkali Metals, their characteristics and differences and how they are
incorporatedinto our every day lives.

2. HYDROGEN
The most abundant element in the universe, hydrogen is alsoa
promising source of "clean" fuel on Earth.
hydrogen makes up more than 90 percent of all of the atoms.
Hydrogen is essential for life, and it is present in nearlyall the
molecules in living things.
The element also occurs in the stars and powers the universe through
the proton-proton reaction and carbon-nitrogen cycle.

3. LITHIUM
Date of Discovery: 1817
Discoverer: Johann Arfvedson
Name Origin: From the Greek word
lithos (stone)
Uses: batteries, ceramics, lubricants
Obtained From: passing electric charge
through melted lithium chloride,

4. SODIUM
• Although sodium is the sixth most abundant element on earth and
comprises about 2.6% of the earth's crust, it is a very reactive element and
is never found free in nature
• Sodium is used in the production of titanium, sodamide, sodium cyanide,
sodium peroxide, and sodium hydride.
• Sodium also forms many useful compounds. Some of the most common
are: table salt (NaCl), soda ash (Na2CO3), baking soda

5. POTASSIUM (K)
• Potassium is a very important mineral for the proper function of all cells,
tissues, and organs in the human body.
• It is also an electrolyte, a substance that conducts electricity in the body,
along with sodium, chloride, calcium, and magnesium.
• Many foods contain potassium, including all meats, some types of fish and
many fruits, vegetables, and legumes.
• Dairy products are also good sources of potassium.

6. RUBIDIUM (RB)
• Rubidium is used in vacuum tubes as a getter, a material that combines with
and removes trace gases from vacuum tubes.
• It is also used in the manufacture of photocells and in special glasses. Since
it is easily ionized, it might be used as a propellant in ion engines on
spacecraft.
• Derived from Lithium

7. CESIUM (CS)
• Cesium has the second lowest melting point of all metallic elements, which
limits its uses.
• Since it is easily ionized and has a high mass, cesium ions may one day be
used as a propellant in ion engines on spacecraft.
• Cesium reacts violently with water and ice, forming cesium hydroxide
(CsOH).
• Cesium hydroxide is the strongest base known and will attack glass.

8. FRANCIUM (Fr)