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 incorporated into our every day lives.

HYDROGENThe most abundant element in the

universe, hydrogen is also a 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 nearly all 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.

LITHIUMDate 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,

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

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.

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

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.

FRANCIUM (Fr)