1. It’s Elemental Get to know your periodic table of elements

2. Group 1 Hydrogen • Hydrogen was discovered in 1766 by Henry Cavendish • Hydrogen is the first element • Even though it is not a metal, it goes ingroup 1because it has one valence electron. • Hydrogen is the most abundant element in the universe. It has Zero neutrons. • Hydrogen has three naturally occurring isotopes • Hydrogen can react like a metal and a non metal by how and when it gives and gains electrons.

3. Group 1 Alkali Metals • Alkali Metals comes from the Arabic al-qili, which means “ashes of the saltwort plant.” • They easily lose their one valence electron • They are soft enough to cut with a knife • They are highly reactive. • Lab samples are stored in oil to prevent reaction to oxygen • They are good conductors of heat and electricity.

4. Alkali Metals • Lithium – Li lightest of the alkali metals • Sodium – Na an abundant alkali metal • Potassium – K nearly as abundant as Na but more reactive • Rubidium – Rbhas low melting point 40° C and combusts when exposed to air • Cesium – Cs lower melting point and more reactive than Rubidium • Francium – Fr a rare radioactive element

5. Lithium uses • Batteries • Pharmaceuticals • Air purifiers

6. Sodium • One of the most abundant of the alkali metals • Essential to human biological functions • Sodium ions are the most common positive ion in the fluids surrounding cells

7. Potassium not just Bananas • Similar in abundance to sodium • Has a low melting point about 63° Celsius. • It can be cut with a knife. • It has a silver appearance. • It is highly reactive with Oxygen and Water, • The water reaction is exothermic.

8. Rubidium • Silvery-white in color • Low melting point about 43° C . • Highly reactive in the air and water. • Discovered by Robert Bunsen and Gustav Kirchhoff in 1861. • No necessity for human biology.

9. Cesium • Melting point is 28* C • Discovered by Bunsen and Kirchoff in 1860 • Highly reactive • Limited uses: used in vacuum tubes to remove trace gases

10. Francium • Highly radioactive • Calculated melting point of about 27° C • Has a half-life of about 22 minutes • Expected to be silvery and reflective. • Low melting point and short half-life limits practical applications.

11. What have we learned? • Elements in column one have very similar properties. • They are all silvery in color. • They all can be cut with a knife. • They all have one valence electron • They all react quickly and sometimes violently with air and water. • They all have increasingly lower melting points.

12. Now your turn!! • Get out your periodic table and label the following information: • 1. the valence electron number for the Representative element groups (1-2 & 13-18) • 2. Label the family names: alkali, alkaline earth, transition metals, halogens, noble gases • 3. Label 1 physical property of 1 element in each group/family. • 4. Give 2 common uses for 1 element in each group/family.