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PERIODIC TABLE
History of the development of the Periodic Table
1. Antoine Lavoisier
a. 1st person to classify elements
b. Group them into 4 groups
3. John Newlands
a. 1st to arrange elements in the
order of increasing atomic mass.
b. Law of Octate, later became Periodic Law.
c. Important to further the developmentof Periodic Table Johann Johann.
2. Johann W. dobereiner
Triad system
elements grouped in 3
4. Lothar Meyer
Graph of atomic volume
against atomic mass show
similar curve with similar
chemical properties.
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4. Dimitri Mendeleev
a. Arrange elements in the order of
increasing mass.
b. Left empty spaces for elements to be
found later.
A modern Periodic table
1. In the Periodic table, elements are arranged in the order of increasing proton
number.
2. Periodic table has 7 rows (Period) and 18 columns (Groups).
3. 1st, 2nd and 3rd are the short periods.
4. Period 4 and 5 are long periods, which included the transition metals.
5. Period 6 is lanthanide series.
6. Period 7 is actinide series.
6. H. J. G. Moseley
a. X-ray frequencies helped to
determine proton numbers.
b. Arranged elements in the order of
increasing proton number.
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GROUP 1 ELEMENTS
Alkali metal
Physical properties
Soft silvery solid, easily cut.
They are malleable and ductile.
They oxidize rapidly in air. Due to oxide coating, its bright, shiny luster is hidden. When the
coating is cut off with a knife, the shiny metal will be clearly visible.
These are good conductors of heat and electricity.
Good electricity conductor free moving valence electrons.
They are highly reactive with water. They are mostly not found in free nature as they react
quickly and vigorously. Some of these metals are stored in kerosene or other mineral oils.
Potassium and sodium metal store in paraffin oil
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Luminant, colorful flame is produced by them when burned with oxygen.
When going down the group,
Li, Na, K, Rb, Cs, Fr
Atomic size increasing
Softer
Density increasing number of protons and neutrons increase
bp, mp decreasing sizes,
Softness of the element down the group increases due to increasing atomic number becausethe metallic bond will decrease with increase in atomic size.
Chemical properties
1. Actively react with oxygen
2. Actively react with chlorine
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3. Reaction with water
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4.
Fun reading
LithiumLithium is the lightest metal discovered yet. It is the only metal that reacts with nitrogen.
Lithium Oxide is Amphoteric (both acid and base characteristics). Except Lithium, other
alkali elements are predominantly ionic. The charge density on Lithium is stronger than other
alkali metals due to which it is extensively hydrated. Lithium was discovered in 1817 by
Johan Arfvedson, during petalite LiAlSi4O10 analysis. The word Lithium is derived from the
Greek word 'lithos' meaning stone. Lithium is found in number of pegmatitic minerals, clays,
brines, oceans, and in all living things.
Uses of Lithium
Lithium is used in heat resistive ceramics and glasses.
Alloy of Lithium is used in aircraft building.
Lithium Deuteride is used as fusion fuel in thermonuclear weapons.
Lithium batteries are packed with lot of energy as compared to other metals. Revolutionized
devices like cell phones, computers use lithium batteries.
Lithium salts are used as mood stabilizing drug.
Lithium-6 is a main source for tritium production.
Lithium is used in deoxidizing copper and copper alloys.
Lithium compounds are used as pyrotechnic colorants in fireworks that produces red
luminance.
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Lubricating greases are produced from Lithium.
Sodium
Sodium is a chemical substance which we consume everyday in our food in the form of
sodium chloride (common salt). Sodium is produced by electrolysis of sodium chloride.
Sodium element is highly reactive. In 1806, Sir Humphry Davy, a chemist, obtained sodium
by passing electric current through molten sodium hydroxide. Sodium was first produced
through nuclear fusion in stars, by fusion of two carbon atoms. It can also be produced in
stars when neon atoms gain a proton.
Uses of Sodium
Sodium is used as luster in metals.
Liquid Sodium is used as coolant in Nuclear reactors.
Sodium salt of fatty acids are used in soap.NaK, an alloy of sodium and potassium, is an important heat transfer agent.
Sodium compounds are used in paper, textile, petroleum and chemical industries.
Sodium Iodide is used to treat extensive ringworm.
Sodium is used in street lights and sodium vapor lamps as it can give yellow glow with bright
luminance.
Sodium hydroxide is used as oven cleaner.
Potassium
Potassium is the 19th element in the periodic table. Potassium plays a vital role in the properfunctioning of our body. It is an essential mineral that should be maintained in organisms. If
potassium level is not balanced it may lead to hyperkalemia or hypokalemia. Potassium turns
gray on exposure to air. To prevent oxidation and to keep out moisture, potassium is stored in
petroleum.
Uses of Potassium
Potassium chloride is essential for the growth of plants. It is used in fertilizers.
Potash improves water retention, yield, nutrient value, taste, color, texture and disease
resistance of food crops.Potassium chlorate and potassium nitrate are used in explosives and fireworks.
Potassium nitrate is used as a food preservative.
Potassium maintains blood pressure and acidity levels in our body.
Potassium chromate is used in the tanning of leather and in the manufacture of inks, gun
powder, dyes, safety matches etc.,
Potassium is essential for normal cell respiration and electrolyte function as 95% of our cells
are made of potassium.
Potassium hydroxide is used to make detergents.
Potassium helps to pump fluids inside the heart and the nerves.
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Rubidium
Rubidium is a radioactive element. It is derived from a latin word rubius meaning deepest
red.
Uses of Rubidium
Rubidium 82 is used in myocardial perfusion.
Rubidium is used in the manufacture of atomic clocks, electronic tubes, photocells.
Rubidium is used as working fluid in vapor turbines.
It is used as a component in the engines of space vehicles.
Rubidium vapor is used in laser cooling.
Rubidium chloride is used to induce cells to take up DNA.
It is used in thermoelectric generators.
Rubidium Carbonate is used in making optical glasses.
Due to hyperfine structure of rubidium's energy levels, it is used in atomic clocks.
A compound made up of rubidium, silver and iodine, has certain electrical characteristics and
is used in making thin film batteries.
Cesium
Cesium is an active metal. Chemically, cesium is the most electropositive element and
combines with anions to form compounds. It is a highly toxic element. Cesium hydroxide isthe strongest base discovered yet. It has many isotopes of which cesium-133 is a stable
isotope and the most important standard for measurement of time (Cesium clocks or atomic
clocks). Cesium is liquid at or near room temperature.
Uses of Cesium
Cesium-134 is used in nuclear power industry.
Used in photoelectric cells due to its quick electron emission.
Cesium is used as catalyst for hydrogenation of certain organic compounds.
It is used in propulsion systems.It removes air traces from vacuum tubes.
Cesium is used in photovoltaic cells, television image devices, night-vision equipment.
Cesium vapor is used in magnetometer.
Cesium-137 is used in brachytherapy to treat cancers. (Brachytherapy is a cancer treatment
method using radioactive elements)
Cesium chloride solution is used in molecular biology for density gradient
ultracentrifugation, primarily for the isolation of viral particles, subcellular organelles and
fractions, and nucleic acids from biological samples.
Cesium is used as a standard in spectrophotometry
It is used in military aircraft.
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Francium
Francium has the lowest electronegativity among all the known elements. It is a highly
radioactive metal and heaviest of these metals. Francium is produced by bombarding thorium
with protons or by bombarding radium with neutrons. This element is rare and is not used
much. It is mainly used for scientific research in laboratory. It decays quickly as it has short
half life.
GROUP 17 ELEM,ENTS
Halogen : Fluorine(F), chlorine(Cl), bromine(Br), iodine(I)
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F2 Cl2 Br2 I2
Gas Gas Liquid Solid
Pale yellow Pale green Brown Black
--------------- size increase ---------------
--------------- reactivity decrease ----------
--------- m/p , b/p increase ( van der waal increase)--
---------- solubility decrease ----------
GROUP 18 ELEMENTS : Noble gas
He, Ne, Ar, Kr, Xe, Rn
Stable electronic structures, He duplet, others octet
Least reactive of all.
Low melting point and boiling point but increase gradually (Van der waals forces increase
with size/mass)
Size increase (no of shell increase)
Mass and density increase.
Uses of noble gases
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The Electron Configurations for Noble Gases: Group 18
Helium 2Neon 2.8Argon 2.8.8Krypton 2.8.18.8Xenon 2.8.18.18.8Radon 2.8.18.32.18.8
Trends within Group 18
Atomic
#
Atomic
mass
Boiling
point
(K)
Melting
point
(K)
Density
(g/dm3)
Atomic
radius/pm
He 2 4.003 4.216 0.95 0.1786 31
Ne 10 20.18 27.1 24.7 0.9002 38
Ar 18 39.948 87.29 83.6 1.7818 71
Kr 36 83.3 120.85 115.8 3.708 88Xe 54 131.29 166.1 161.7 5.851 108
Rn 86 222.1 211.5 202.2 9.97 120
The Atomic and Physical Properties Atomic mass, boiling point and atomic radii INCREASE down a group in the
periodic table.
The first ionization energy, DECREASES down a group in the periodic table.
The noble gases have the largest ionization energies which reflects their chemical
inertness.
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As you go down group 18, atomic radius and inter-atomic
forces INCREASES resulting in anINCREASED melting point, boiling point,
enthalpy of vaporization and solubility.
Group 18's INCREASE in density is correlated to the INCREASE in atomic mass.
Because they are INCREASING in atomic size, the electron clouds of these non
polar atoms become increasingly polarized which leads to weak van Der Waals forces
among the atoms. Thus, the formation of liquids and solids is more easily attainable
for these heavier elements because of their melting and boiling points.
Because noble gases outer shell is full, they are extremely stable, not tending to form
chemical bonds and have a low tendency to gain or lose electrons.
Under standard conditions the members of the noble gas group behave similarly.
All are monotomic gases under standard conditions.
Noble gas atoms, like other atoms in other groups, INCREASE steadily in atomic
radius from one period to the next due to the INCREASING number of electrons.
The size of the atom is positively correlated to several properties of noble gases. The
ionization potential DECREASES with an INCREASING radius, because the
valence electrons in the larger noble gases are further away from the nucleus, so they
are not being held as tightly together by the atom.
The attractive force INCREASES with the size of the atom as a result of
an INCREASE in polarizability and thus a DECREASE in ionization potential.
Overall, noble gases have weak interatomic forces, and therefore very low boiling andmelting points compared to other group elements.
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Helium
Helium can be found in
balloons!
Neon
One of the many
colors of neon lights.
Neon
Argon plasma light bulb.
Kripton
Krypton laser.
Xenon
Xenon headlights found in
BMW cars.
Radon
Radon bath
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PATTERN OF PROPERTIES IN A PERIOD
Na Mg Al Si P S Cl Ne
Solid Solid Solid Solid Solid Solid Gas Gas
Metal Metal Metal Metalloid Non
metal
Non
metal
Non
metal
Non
metal
Melting and boiling point
Electricity conductivity
TRANSITION METALSc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn
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The History Behind Noble Gases
The first person who set apart and characterized the presence of thesenoble gases was Henry Cavendish in 1875. Cavendish was able todistinguish these elements by chemically removing all the oxygen andnitrogen from a receptacle containing air. The nitrogen was oxidized toNO2 by electric discharges and absorbed by a sodium hydroxidesolution. The remaining oxygen was then removed from the mixture.Interestingly, the experiment revealed that 1/120 of the gas volumeremained un-reacted in the receptacle. The second person who wasable to isolate, but not typify them was William Francis (1855-1925).Francis did this by noting the formation of gas while dissolvingUranium containing minerals in acid.
Argon
In 1894, John William Strutt discovered that pure nitrogen, chemicallyobtained, was less dense compared to "pure" nitrogen isolated fromair. From this breakthrough, he concluded that something else was inthe air. With the aid and collaboration with William Ramsay, the twowere able to replicate and modify Cavendish's experiment to get abetter understanding of the un-reactive fraction of air in his original
experiment. Different from Cavendish, Strutt and Ramsay removed theoxygen by reacting it with copper and nitrogen was removed byreacting it with magnesium. The remaining fraction was properlycharacterized and the new element was named 'Argon' which camefrom the Greek word 'inert'.
Helium
Helium was first discovered as a bright yellow line with a wavelength of
587.49 nanometers from the sun in 1868. This discovery was made byPierre Jansen. Jansen initially assumed that it was sodium. However,later studies by Sir William Ramsay (who isolated helium on Earth bytreating a variety of rare elements with acids) confirmed that thebright yellow line that came out of the experiment matched up with thespectrum of the sun. From this, British physicist William Crookes wasable to identify it as helium.
Neon, Krypton, Xenon
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These noble gases discovered by Morris W. Travers and Sir WilliamRamsay in 1898. Ramsay discovered Neon by chilling a sample of theatmosphere until liquid phase, then captured the gases as the boiledoff by warming up the liquid. Krypton and Xenon were both discoveredthrough this process.
Radon
In 1900, while studying radium's decay chain, Friedrich Earns Dorndiscovered the last noble gas in group 18; Radon. Through someexperiments, Dorn noticed that radium compounds emanatedradioactive gas. This radioactive gas was originally named niton afterthe Latin word "nitens". By 1923, the International Committee forChemical Elements and International Union of Pure Applied Chemistry
(IUPAC) decided to name the element as Radon. All isotopes of radonare radioactive. Radon-222 has the longest half-life - less than 4 days,and is an alpha-decay product of Radium-226, part of the U-238 to Pb-206 radioactive decay chain.
For covalently-bonded diatomic and polyatomic gases, heat capacityconsists of translational, rotational, and vibrational fractions. Sincemonatomic gases such as noble gases have no bonds, they cannotabsorb heat as bond vibrations. Since the center of mass of
monatomic gases is at the nucleus of the atom, and the mass of theelectrons is negligible compared to the nucleus, the kinetic energy dueto rotation is negligible compared to the kinetic energy of translation,unlike in di- or polyatomic molecules where rotation of nuclei aroundthe center of mass of the molecule contributes to the heat capacity.Therefore, the internal energy per mole of a monatomic noble gasequals its translational contribution = (3/2) R T, where R = universalgas constant and T = absolute temperature.
For monatomic gases at a given temperature, the average kinetic
energy due to translations of the atoms is practically equal regardlessof the element. Therefore at a given temperature, the heavier theatom, the more slowly its gas atoms will move. Monatomic gas meanvelocity DECREASES with increasing molecular mass, and given thesimplified heat capacity situation, noble gaseous thermal conductivityDECREASES with increasing molecular mass.
The Uses of Noble Gases in Everyday Life
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Helium
is used as a component of breathing gases due to its low solubility influids or lipids. For example, gases are absorbed by the blood and
body tissues when under pressure during scuba diving. Because of itsreduced solubility, little helium is taken into cell membranes, when itreplaces part of the breathing mixture, helium causes a decrease in thenarcotic effect of the gas at far depths. The reduced amount ofdissolved gas in the body means fewer gas bubbles form decreasingthe pressure of the ascent. Helium and Argon are used to shieldwelding arcs and the surrounding base metal from the atmosphereduring welding.
Helium can be found in balloons!
Helium is used in very low temperature cryogenics, particularly formaintaining superconductors at a very low temperature.Superconductivity is useful for creating very strong magnetic fields.Helium is also the most common carrier gas in gas chromatography.
Neon
is used for many applications that we see in daily life. For examples:
Neon lights, fog lights, TV cine-scopes, lasers, voltagedetectors, luminous warnings and also advertising signs. The mostpopular applications of Neon would be the Neon tubes that we see foradvertisement or elaborate decorations. These neon tubes consist withneon and helium or argon under low pressure submitted to electricaldischarges. The color of emitted light shown is dependent on thecomposition of the gaseous mixture and also with the color of the glassof the tube. Pure Neon within a colorless tube can obtain a red light,which reflects a blue shine. These reflected light are also known asfluorescent light.
Argon
Argon is used for a diverse group of applications in the growingindustries of : electronics, lighting, glass, and metal fabrications. Argonis used in electronics to provide a protective heat transfer medium forultra-pure semiconductors from silicon crystals and for growinggermanium. Argon can also fill fluorescent and incandescent lightbulbs; creating the blue light found in neon type lamps. By utilizingargon's low thermal conductivity, window manufacturers can provide agas barrier needed to produce double-pane insulated windows. This
http://chemwiki.ucdavis.edu/Analytical_Chemistry/Instrumental_Analysis/Chromatography/Gas_Chromatographyhttp://chemwiki.ucdavis.edu/Analytical_Chemistry/Instrumental_Analysis/Chromatography/Gas_Chromatography -
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Radon
Radon has been said to be the second most frequent cause of lungcancer, after cigarette smoking. However, it can be found in various
beneficial applications as well. For examples through: radiotherapy,relief from arthritis, and bathing. In radiotherapy, radon has been usedin implantable seeds, made of glass or gold, primarily used to treatcancers. For arthritis, its been said that exposure to radon mitigatesauto-immune diseases such as arthritis. Those who have arthritis haveactually sought limited exposure to radioactive mine water and radonto relief their pain. However, radon has nevertheless found to inducebeneficial long-terms effect. Some places actually have "Radon Spas".For examples: Bad Gastern, Austria and Japanese Onsen in Misasa,Tottori. "Radon Spa" is a relieving therapy where people sit for minutes
to hours in a high-radon atmosphere, believing that low doses ofradiation will boost up their energy.
Radon bath.Uses of Alkali Metals
In IUPAC (International Union of Pure and Applied Chemistry)
nomenclature, alkali metals or Group 1A elements belong to group 1A in
the periodic table. Scroll down to learn about the uses of alkali metals.
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Alkali metals or Group 1A elements belong to a common group due to its
ns1 valence electronic configuration. The properties of an element have
periodic dependence on its atomic number but not on atomic weight.
These are similar to Group 17 (Halogens) in a way that, it attains noble
gas configuration after losing its valence electron. That is why hydrogen is
placed separately in the periodic table. Alkali elements belong to s-block,
including hydrogen.
Properties
These metals are soft, shiny, silvery white elements.
They are highly reactive with water. They are mostly not found in free
nature as they react quickly and vigorously. Some of these metals are
stored in kerosene or other mineral oils.
They oxidize rapidly in air. Due to oxide coating, its bright, shiny luster is
hidden. When the coating is cut off with a knife, the shiny metal will be
clearly visible.Luminant, colorful flame is produced by them when burned with oxygen.
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These have low ionization enthalpy (heat evolved when an atom gets
ionized).
These are strong reducing agents.
They are malleable and ductile.
Softness of the element down the group increases due to increasingatomic number because the metallic bond will decrease with increase in
atomic size.
The ionization energy of group 1A elements decreases down the group.
These are good conductors of heat and electricity.
Element Symbol Atomic
number Electronic
configuration Melting
point Boilingpoint
Lithium Li 3 1s22s1 180.54C 1342C
Sodium Na 11 3s1 97.72C 883C
Potassium K 19 4s1 63.38C 759C
Rubidium Rb 37 5s1 39.31C 688C
Cesium Cs 55 6s1 28.44C 671C
Francium Fr 87 7s1 27C 677C
Lithium
Lithium is the lightest metal discovered yet. It is the only metal that reacts with nitrogen.
Lithium Oxide is Amphoteric (both acid and base characteristics). Except Lithium, other
alkali elements are predominantly ionic. The charge density on Lithium is stronger than other
alkali metals due to which it is extensively hydrated. Lithium was discovered in 1817 by
Johan Arfvedson, during petalite LiAlSi4O10 analysis. The word Lithium is derived from the
Greek word 'lithos' meaning stone. Lithium is found in number of pegmatitic minerals, clays,
brines, oceans, and in all living things.
Uses of Lithium
Lithium is used in heat resistive ceramics and glasses.
Alloy of Lithium is used in aircraft building.
Lithium Deuteride is used as fusion fuel in thermonuclear weapons.
Lithium batteries are packed with lot of energy as compared to other metals. Revolutionized
devices like cell phones, computers use lithium batteries.
Lithium salts are used as mood stabilizing drug.
Lithium-6 is a main source for tritium production.
Lithium is used in deoxidizing copper and copper alloys.
Lithium compounds are used as pyrotechnic colorants in fireworks that produces red
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luminance.
Lubricating greases are produced from Lithium.
Sodium
Sodium is a chemical substance which we consume everyday in our food in the form ofsodium chloride (common salt). Sodium is produced by electrolysis of sodium chloride.
Sodium element is highly reactive. In 1806, Sir Humphry Davy, a chemist, obtained sodium
by passing electric current through molten sodium hydroxide. Sodium was first produced
through nuclear fusion in stars, by fusion of two carbon atoms. It can also be produced in
stars when neon atoms gain a proton.
Uses of Sodium
Sodium is used as luster in metals.
Liquid Sodium is used as coolant in Nuclear reactors.
Sodium salt of fatty acids are used in soap.
NaK, an alloy of sodium and potassium, is an important heat transfer agent.
Sodium compounds are used in paper, textile, petroleum and chemical industries.
Sodium Iodide is used to treat extensive ringworm.
Sodium is used in street lights and sodium vapor lamps as it can give yellow glow with bright
luminance.
Sodium hydroxide is used as oven cleaner.
Potassium
Potassium is the 19th element in the periodic table. Potassium plays a vital role in the properfunctioning of our body. It is an essential mineral that should be maintained in organisms. If
potassium level is not balanced it may lead to hyperkalemia or hypokalemia. Potassium turns
gray on exposure to air. To prevent oxidation and to keep out moisture, potassium is stored in
petroleum.
Uses of Potassium
Potassium chloride is essential for the growth of plants. It is used in fertilizers.
Potash improves water retention, yield, nutrient value, taste, color, texture and disease
resistance of food crops.
Potassium chlorate and potassium nitrate are used in explosives and fireworks.
Potassium nitrate is used as a food preservative.
Potassium maintains blood pressure and acidity levels in our body.
Potassium chromate is used in the tanning of leather and in the manufacture of inks, gun
powder, dyes, safety matches etc.,
Potassium is essential for normal cell respiration and electrolyte function as 95% of our cells
are made of potassium.
Potassium hydroxide is used to make detergents.
Potassium helps to pump fluids inside the heart and the nerves.
Rubidium
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Rubidium is a radioactive element. It is derived from a latin word rubius meaning deepest
red.
Uses of Rubidium
Rubidium 82 is used in myocardial perfusion.Rubidium is used in the manufacture of atomic clocks, electronic tubes, photocells.
Rubidium is used as working fluid in vapor turbines.
It is used as a component in the engines of space vehicles.
Rubidium vapor is used in laser cooling.
Rubidium chloride is used to induce cells to take up DNA.
It is used in thermoelectric generators.
Rubidium Carbonate is used in making optical glasses.
Due to hyperfine structure of rubidium's energy levels, it is used in atomic clocks.
A compound made up of rubidium, silver and iodine, has certain electrical characteristics and
is used in making thin film batteries.
Cesium
Cesium is an active metal. Chemically, cesium is the most electropositive element and
combines with anions to form compounds. It is a highly toxic element. Cesium hydroxide is
the strongest base discovered yet. It has many isotopes of which cesium-133 is a stable
isotope and the most important standard for measurement of time (Cesium clocks or atomic
clocks). Cesium is liquid at or near room temperature.
Uses of CesiumCesium-134 is used in nuclear power industry.
Used in photoelectric cells due to its quick electron emission.
Cesium is used as catalyst for hydrogenation of certain organic compounds.
It is used in propulsion systems.
It removes air traces from vacuum tubes.
Cesium is used in photovoltaic cells, television image devices, night-vision equipment.
Cesium vapor is used in magnetometer.
Cesium-137 is used in brachytherapy to treat cancers. (Brachytherapy is a cancer treatment
method using radioactive elements)
Cesium chloride solution is used in molecular biology for density gradient
ultracentrifugation, primarily for the isolation of viral particles, subcellular organelles and
fractions, and nucleic acids from biological samples.
Cesium is used as a standard in spectrophotometry
It is used in military aircraft.
Francium
Francium has the lowest electronegativity among all the known elements. It is a highly
radioactive metal and heaviest of these metals. Francium is produced by bombarding thorium
with protons or by bombarding radium with neutrons. This element is rare and is not usedmuch. It is mainly used for scientific research in laboratory. It decays quickly as it has short
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half life.