GROUP 1 AND 2 METALS Physical and chemical Properties

The ppt deals with members of group 1 and group 2 of the periodic table. It describes the trend in physical and chemical properties on going down. It also describes chemical reactions of these members with water and air.

1. GROUP 1 AND 2 METALS

2. The Group I metals The Group I metals are also called the alkali metals as they form  alkaline solutions  with high pH values when reacted with water Group 1 metals are lithium, sodium, potassium, rubidium, cesium and francium They all contain just  one   electron  in their outer shell

3.  the trend in reactivity in Group I The reactivity of the Group 1 metals increases as you go down the group Each outer shell contains only one electron so when they react, they lose the outer electron which empties the outermost shell The next shell down automatically becomes the outermost shell and is  already full , hence the atom obtains an electronic configuration which has a full outer shell of electrons As you go down Group 1, the number of shells of electrons increases by 1 (Period number increases down the Periodic table)

4. the trend in reactivity in Group I This means that the outer electron is  further  away from the nucleus so there are  weaker  electrostatic forces of attraction This requires  less energy  to overcome the electrostatic forces of attraction between the negatively charged electron and the positively charged nucleus This allows the electron to be lost easily, making it more reactive as you go down the Group

5. Physical properties of the Group I metals Are soft and easy to cut, getting  softer  and  denser  as you move down the Group (sodium and potassium do not follow the trend in density) Have  shiny  silvery surfaces when freshly cut Conduct  heat  and  electricity They all have  low  melting points and  low  densities and the melting point  decreases  as you move down the Group

6. Chemical properties of the Group I metals They react readily with oxygen and water vapour in air so they are usually kept under  oil  to stop them from reacting Group 1 metals will react similarly with water, reacting vigorously to produce an  alkaline  metal hydroxide solution and  hydrogen  gas

7. Reactions of the Group I metals and water

8. Electronic configuration in Group I

9. Lithium Lithium (Li) , chemical element of Group 1 ( Ia ) in the periodic table, the alkali metal group, lightest of the solid elements. The metal itself—which is soft, white, and lustrous—and several of its alloys and compounds are produced on an industrial scale. atomic number 3 atomic weight 6.941 melting point 180.5 °C (356.9 °F) boiling point 1,342 °C (2,448 °F) specific gravity 0.534 at 20 °C (68 °F) oxidation state +1 electron configuration 2-1 or 1 s 2 2 s 1

10. Sodium Sodium (Na) , chemical element of the alkali metal group (Group 1 [ Ia ]) of the periodic table. Sodium is a very soft silvery-white metal. Sodium is the most common alkali metal and the sixth most abundant element on Earth, comprising 2.8 percent of Earth’s crust. It occurs abundantly in nature in compounds, especially common salt—sodium chloride ( NaCl )—which forms the mineral halite and constitutes about 80 percent of the dissolved constituents of seawater. atomic number 11 atomic weight 22.9898 melting point 97.81 °C (208 °F) boiling point 882.9 °C (1,621 °F) specific gravity 0.971 (20 °C) oxidation states +1, −1 (rare) electron configuration 2-8-1 or 1 s 2 2 s 2 2 p 6 3 s 1

11. Potassium Potassium (K) , chemical element of Group 1 ( Ia ) of the periodic table, the alkali metal group, indispensable for both plant and animal life. Potassium was the first metal to be isolated by electrolysis, by the English chemist Sir Humphry Davy, when he obtained the element (1807) by decomposing molten potassium hydroxide (KOH) with a voltaic battery. atomic number 19 atomic weight 39.098 melting point 63.28 °C (145.90 °F) boiling point 760 °C (1,400 °F) specific gravity 0.862 (at 20 °C, or 68 °F) oxidation states +1, −1 (rare) electron configuration 2-8-8-1 or 1 s 2 2 s 2 2 p 6 3 s 2 3 p 6 4 s 1

12. Rubidium Rubidium ( Rb ) , chemical element of Group 1 ( Ia ) in the periodic table, the alkali metal group. Rubidium is the second most reactive metal and is very soft, with a silvery-white lustre . atomic number 37 atomic weight 85.47 melting point 38.9 °C (102 °F) boiling point 688 °C (1,270 °F) specific gravity 1.53 (at 20 °C, or 68 °F) oxidation states +1, -1 (rare) electron config. 2-8-18-8-1 or [Kr]5 s 1

13. Cesium Cesium (Cs) , also spelled  caesium , chemical element of Group 1 (also called Group Ia ) of the periodic table, the alkali metal group, and the first element to be discovered spectroscopically (1860), by German scientists Robert Bunsen and Gustav Kirchhoff, who named it for the unique blue lines of its spectrum (Latin  caesius , “sky-blue”). atomic number 55 atomic weight 132.90543 melting point 28.44 °C (83.19 °F) boiling point 671 °C (1,240 °F) specific gravity 1.873 (at 20 °C, or 68 °F) oxidation states +1, -1 (rare) electron config. 2-8-18-18-8-1 or [ Xe ]6 s 1

14. Francium Francium (Fr) , heaviest chemical element of Group 1 ( Ia ) in the periodic table, the alkali metal group. It exists only in short-lived radioactive forms. Natural francium cannot be isolated in visible, weighable amounts, for only 24.5 grams (0.86 ounce) occur at any time in the entire crust of Earth.  atomic number 87 stablest isotope (223) oxidation state +1 electron config. 2-8-18-32-18-8-1 or [Rn] 7 s 1

15. The Group II metals Elements in group 2 of the periodic table are called alkaline Earth metals. They are silvery or gray in color. They are also relatively soft and low in density. Alkaline Earth metals are very reactive because they readily give up their two valence electrons to achieve a full outer energy level, which is the most stable arrangement of electrons. Reactivity increases from the top to the bottom of the group. Examples of alkaline Earth metals include calcium, which is needed for strong bones, and strontium, which is used for making cement and other products.

16.  the trend in reactivity in Group II The  reactivity  of  alkaline Earth metals  increases from the top to the bottom of the group. That's because the atoms get bigger from the top to the bottom, so the valence electrons are farther from the nucleus. Alkaline Earth metals are very reactive because they readily give up their two valence electrons to achieve a full outer energy level, which is the most stable arrangement of electrons. Reactivity increases from the top to the bottom of the group.

17. Properties of the Group II metals They are harder than those in Group I. They are silvery-grey in colour when pure and clean. They tarnish quickly, however, when left in air due to the formation of a metal oxide on their surface. They are good conductors of heat and electricity. They burn in oxygen or air with characteristic flame colours to form solid white oxides. For example: magnesium + oxygen → magnesium oxide 2Mg(s) + O2(g) → 2MgO(s)

18. Properties of the Group II metals They react with water, but they do so much less vigorously than the elements in Group I. For example: calcium +) water → calcium hydroxide + hydrogen gas Ca(s) + 2H2O(l) → Ca(OH)2( aq ) H2(g) Considering the group as a whole, the further down the group you go, the more reactive the elements become.

19. Reactions of the Group II metals and water

20. Electronic configuration in Group II

21. Beryllium Beryllium (Be) , formerly (until 1957)  glucinium , chemical element, the lightest member of the alkaline-earth metals of Group 2 (IIa) of the periodic table, used in metallurgy as a hardening agent and in many outer space and nuclear applications. atomic number 4 atomic weight 9.0122 melting point 1,287 °C (2,349 °F) boiling point 2,471 °C (4,480 °F) specific gravity 1.85 at 20 °C (68 °F) oxidation state +2 electron configuration 1 s 2 2 s 2

22. Magnesium Magnesium (Mg) , chemical element, one of the alkaline-earth metals of Group 2 (IIa) of the periodic table, and the lightest structural metal. Its compounds are widely used in construction and medicine, and magnesium is one of the elements essential to all cellular life. atomic number 12 atomic weight 24.305 melting point 650 °C (1,202 °F) boiling point 1,090 °C (1,994 °F) specific gravity 1.74 at 20° C (68 °F) oxidation state +2 electron configuration 1 s 2 2 s 2 2 p 6 3 s 2

23. Calcium Calcium (Ca) , chemical element, one of the alkaline-earth metals of Group 2 (IIa) of the periodic table. It is the most abundant metallic element in the human body and the fifth most abundant element in Earth’s crust. atomic number 20 atomic weight 40.078 melting point 842 °C (1,548 °F) boiling point 1,484 °C (2,703 °F) specific gravity 1.55 (20 °C, or 68 °F) oxidation state +2 electron configuration 1 s 2 2 s 2 2 p 6 3 s 2 3 p 6 4 s 2

24. Strontium Strontium ( Sr ) , chemical element, one of the alkaline-earth metals of Group 2 (IIa) of the periodic table. It is used as an ingredient in red signal flares and phosphors and is the principal health hazard in radioactive fallout. atomic number 38 atomic weight 87.62 melting point 769 °C (1,416 °F) boiling point 1,384 °C (2,523 °F) specific gravity 2.63 oxidation state +2 electron configuration [Kr]5 s 2

25. Barium Barium (Ba) , chemical element, one of the alkaline-earth metals of Group 2 (IIa) of the periodic table. The element is used in metallurgy, and its compounds are used in pyrotechnics, petroleum production, and radiology. atomic number 56 atomic weight 137.33 melting point 727 °C (1,341 °F) boiling point 1,805 °C (3,281 °F) specific gravity 3.51 (at 20 °C, or 68 °F) oxidation state +2 electron configuration [ Xe ]6 s 2

26. Radium Radium (Ra) , radioactive chemical element, the heaviest of the alkaline-earth metals of Group 2 (IIa) of the periodic table. Radium is a silvery white metal that does not occur free in nature. atomic number 88 stablest isotope 226 melting point about 700 °C (1,300 °F) boiling point not well established (about 1,100–1,700 °C [2,000–3,100 °F]) specific gravity about 5 oxidation state +2 electron configuration [Rn]7 s 2