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Alkali Metals. Grayson Johnson Emily Pona Kara Sherman Joe Baylor. Elements in Group. Lithium (Li) Sodium (Na) Potassium (K) Rubidium (Rb) Cesium (Cs) Francium (Fr). Atomic Numbers and Mass. Li- 3; 6.841amu Na- 11; 27.989768amu K- 19; 39.0983amu Rb- 37; 85.4678amu
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Alkali Metals Grayson Johnson Emily Pona Kara Sherman Joe Baylor
Elements in Group • Lithium (Li) • Sodium (Na) • Potassium (K) • Rubidium (Rb) • Cesium (Cs) • Francium (Fr)
Atomic Numbers and Mass • Li- 3; 6.841amu • Na- 11; 27.989768amu • K- 19; 39.0983amu • Rb- 37; 85.4678amu • Cs- 55;132.90546amu • Fr- 87; 223.0197amu
Valence Electrons and Electron Configurations • Each has 1 valence electron • Li- 1s12s1 • Na- [Ne] 3s11 • K- [Ar] 4s1 • Rb- [Kr] 5s1 • Cs- [Xe] 6s1 • Fr- [Rn] 7s1 Sodium
Melting and Boiling Points • Li-M: 97.72C; B: 883C • Na-M: 180.5C; B: 1342C • K-M: 68.38C; B: 759.0C • Rb-M: 39.31C; B: 688.0C • Cs-M: 28.5C; B: 678.4C • Fr-M: 27.0C; B: 677.0C Rubidium
Color And Atomic size • Li- silver • Na- silver • K- silver • Rb- silver - white • Cs- silver • Fr- unknown metallic is accepted; 270pm
Density and Crystal Structure • Li- 0.53g/cm3 • Na- 0.971g/cm3 • K- 0.862g/cm3 • Rb- 1.53g/cm3 • Cs- 1.873g/cm3 • Fr-@293k: 1.873g/cm3 • All crystal structures are cubic/ body centered cubic
1st Ionization Energy and Electronegativity • Li- 502.2kJ mol-1; 0.98 (pauling scale) • Na- 9.548kJ mol-1; 0.93 • K- 418.8kJ mol-1; 0.82 • Rb- 403kJ mol-1; 0.82 • Cs- 589.8kJ mol-1; 0.79 • Fr- 384kJmol-1; 0.7 (lowest)
Ion Formation, Charge, and Size • All lose one electron and are smaller than the original • All positively charged • Li- 76 • Na- 102 • K- 138 • Rb- 152 • Cs- 167 • Fr- 180
Properties • Li- Reacts with oxygen to form monoxide and peroxide, tarnishes easily with oxygen, only one that forms a nitrate • Na- Reacts quickly with water, ice, and snow • K- Soft easily cut, tarnishes easily with oxygen, actually catches fire when it begins to react with water, reacts vigorously with all halogens • Rb- Reacts violently with water and even ice at 100 degrees C • Cs- Reacts explosively in water to produce cesium hydroxide, extremely strong base that can rapidly corrode glass • Fr- Highly radioactive, 22min half life
Compounds Formed • Li- Lithium Hydride, Lithium Fluoride, Lithium Chloride • Na- Sodium Hydride, Sodium Chloride, Sodium Fluoride • K- K2O, KH, KCI • Rb- Rb2O, Rb2O2, RbH, RbCI • Cs- Cs2O, Cs2, Cs2O2, CsH, CsCI • Fr- none
Uses • Li- Rechargeable (and non) lithium batteries • Na- modify alloys (ex. Aluminum silicon) • K- Used as an electrolyte in batteries and to make soap, explosive in gunpowder, healthy alternative to salt • Rb- Used in dating rocks, purple fireworks, making glasses and ceramics, removes trace gases • Cs- Removes air traces in vacuum cleaners • Fr- too unstable, therefore research purposes only
Strange Facts • Francium completed the discovery of naturally occurring elements (all found after were man-made.) • Cesium is the most alkaline of all the elements and is an extremely reactive metal • Francium is the least electronegative of all
Exceptions • Rubidium and Francium are the only ones without the accepted silver color • Lithium is the only one of group 1 that produces a nitrate when it reacts with Nitrogen