Group IA table of elements

Table of elements Group

IA

LithiumLi

Definition of the Lithium Lithium is a chemical element with

symbol Li and atomic number 3. It is a soft, silver-white metal belonging

to the alkali metal group of chemical elements. Under standard conditions it is the lightest metal and the least dense solid element.

Like all alkali metals, lithium is highly reactive and flammable. For this reason, it is typically stored in mineral oil. When cut open, lithium exhibits a metallic luster, but contact with moist air corrodes the surface quickly to a dull silvery gray, then black tarnish.

Definition of the Lithium Lithium metal is soft enough to be cut with a

knife. When cut, it possesses a silvery-white color that quickly changes to gray due to oxidation.

It is a good conductor of heat and electricity as well as a highly reactive element, though the least reactive of the alkali metals.

When placed over a flame, lithium compounds give off a striking crimson (a strong, deep red color) color, but when it burns strongly the flame becomes a brilliant silver. Lithium will ignite and burn in oxygen when exposed to water or water vapors. Lithium is flammable, and it is potentially explosive when exposed to air and especially to water

Occurrence of the Lithium

Lithium is produced in younger stars. Though it transmutes into two atoms of helium due to collision with a proton.

Although lithium is widely distributed on Earth, it does not naturally occur in elemental form due to its high reactivity.

The total lithium content of seawater is very large and is estimated as 230 billion tonnes.

Lithium is found in trace amount in numerous plants, plankton, and invertebrates.

SodiumNA

Definition of the Sodium Element A soft, light, extremely malleable

silver-white metallic element that reacts explosively with water, is naturally abundant in combined forms, especially in common salt, and is used in the production of a wide variety of industrially important compounds.

Origin / Meaning of the name Sodium Sodium, referred to as

soda by the English, was isolated in 1807 by Sir Humphry Davy through the electrolysis of caustic soda. The symbol of the element is Na which comes for the Latin name for a common sodium compound called natrium (from the Greek 'nítron' a natural salt).

Periodic Table Group and Classification of the Sodium Element Elements can be classified based on their

physical states (States of Matter). This element is a solid. Sodium is classified as an "Alkali Metal" and located in Group 1 elements of the Periodic Table. An Element classified as an Alkali Metal is a very reactive metal that does not occur freely in nature. Alkali metals are soft, malleable, ductile, and are good conductors of heat and electricity. Nearly 75% of all the elements in the Periodic Table are classified as metals which are detailed in the List of Metals.

Occurrence of the Sodium Element Sodium makes up about 2.6% of the

Earth's crust Fourth most abundant element Relatively abundant in stars

Abundances of the elements in different environments • in Universe 0.002% • in Sun 0.004% • in Meteorites 0.55% • in Earth's Crust 2.3% • in Oceans 1.1% • in Humans 0.14%

Precautions Care is required in handling elemental

sodium, as it generates flammable hydrogen and caustic sodium hydroxide upon contact with water; powdered sodium may spontaneously explode in the presence of oxygen

PotassiumK

Definition of Potassium A soft, silver-white, highly or explosively

reactive metallic element that occurs in nature only in compounds.

Potassium is silvery when first cut but it oxidizes rapidly in air and tarnishes within minutes, so it is generally stored under oil or grease. It is light enough to float in water, with which it reacts instantly to release Hydrogen that burns with a lilac flame.

It is obtained by electrolysis of its common hydroxide and found in, or converted to, a wide variety of salts used especially in fertilizers and soaps. The Atomic Number of this element is 19 and the Element Symbol is K.

Definition of Potassium Potassium is the second least dense metal

after lithium. It is a soft solid that has a low melting point and can easily be cut with a knife. Freshly cut potassium is silvery in appearance, but it begins to tarnish toward gray immediately after being exposed to air.

Potassium is an extremely active metal, which reacts violently with oxygen and water in air. With oxygen it forms potassium peroxide, and with water potassium hydroxide. The reaction of potassium with water is dangerous because of its violent exothermic character and the production of hydrogen gas.

Discovery of Potassium The name was coined

by Sir Humphry Davy and originates from the Medieval Latin word kalium (hence the symbol 'K') for potash. This is because the substance was originally obtained by soaking wood ashes in water and evaporating the mixture in an iron pot.

Occurrence of Potassium Potassium is a constituent of many common

rocks and minerals, and is therefore a rather abundant element, though not so abundant as Sodium. Feldspar, which occurs both by itself and as a constituent of granite, contains considerable potassium. The element is a constituent of all clay and of mica and also occurs in very large deposits at Stassfurt, Germany, in the form of the chloride and sulphate, associated with compounds of sodium and Magnesium. In small quantities it is found as nitrate and in many other forms. Refer to Potassium Reaction for its reaction to Water, Oxygen & Acids.

Applications of Potassium Potassium ions are an essential component

of plant nutrition and are found in most soil types. They are used as a fertilizer in agriculture, horticulture, and hydroponic culture.

The potassium cation is a nutrient necessary for human life and health. Potassium chloride is used as a substitute for table salt by those seeking to reduce sodium intake so as to control hypertension.

Precautions of Potassium This reaction is exothermic and releases

enough heat to ignite the resulting hydrogen. It in turn may explode in the presence of oxygen. Potassium hydroxide is a strong alkali that causes skin burns. Finely divided potassium will ignite in air at room temperature. The bulk metal will ignite in air if heated.

Potassium reacts violently with halogens and will detonate in the presence of bromine. It also reacts explosively with sulfuric acid. During combustion potassium forms peroxides and superoxides.

Rubidium

Rb

Definition of Rubidium Rubidium is a chemical element with the

symbol Rb and atomic number 37. Rubidium is a soft, silvery-white metallic element of the alkali metal group, with an atomic mass of 85.4678. Elemental rubidium is highly reactive, with properties similar to those of other alkali metals, such as very rapid oxidation in air.

Rubidium is a very soft, ductile, silvery-white metal. It is the second most electropositive of the non-radioactive alkali metals and melts at a temperature of 39.3 °C (102.7 °F). Similar to other alkali metals, rubidium metal reacts violently with water, forms amalgams with mercury and alloys with gold, iron, cesium, sodium, and potassium, but not lithium.

Discovery of Rubidium Rubidium was discovered in 1861

spectroscopically by Robert Bunsen and Gustav Kirchoff as an impurity associated with samples of the mineral lepidolite (a form of mica). The name rubidium (from the Latin "rubidus" - dark red) was coined for its bright red spectroscopic lines.

Rubidium salts were isolated by Bunsen by precipitation from spring waters - along with salts of other Group 1 elements. He was able to separate them and isolated the chloride and the carbonate. He isolated rubidium metal by reducing rubidium hydrogen tartrate with carbon.

Occurrence of Rubidium Rubidium is the twenty-third most abundant

element in the Earth's crust, roughly as abundant as zinc and rather more common than copper. It occurs naturally in the minerals leucite, pollucie, carnallite, and zinnwaldite, which contain up to 1% of its oxide. Lepidolite contains between 0.3% and 3.5% rubidium, and is the commercial source of the element. Some potassium minerals and potassium chlorides also contain the element in commercially significant amounts

Applications of Rubidium Rubidium compounds are sometimes used in

fireworks to give them a purple color. Rubidium has also been considered for use in a thermoelectric generator using the magnetohydrodynamic principle, where rubidium ions are formed by heat at high temperature and passed through a magnetic field.

Cesium

Cs

Definition of Cesium A soft, silvery-white ductile metal, liquid at room

temperature, the most electropositive and alkaline of the elements, used in photoelectric cells and to catalyze hydrogenation of some organic compounds. Cesium reacts explosively with cold water, and reacts with ice at temperatures above -116°C. Tiny quantities of cesium chloride are found in mineral springs and in seawater. The Atomic Number of this element is 55 and the Element Symbol is Cs.

Caesium metal is highly reactive and very pyrophoric. In addition to igniting spontaneously in air, it reacts explosively with water even at low temperatures, more so than other members of the first group of the periodic table.

Discovery of Cesium In 1860, Robert Bunsen and Gustav Kirchhoff

discovered cesium in the mineral water from Dürkheim, Germany. Due to the bright blue lines in its emission spectrum, they chose a name derived from the Latin word caesius, meaning sky-blue Cesium was the first element to be discovered spectroscopically, only one year after the invention of the spectroscope by Bunsen and Kirchhoff.

Occurrence of Cesium Cesium is found in the mineral pollux, or

pollucite, which occurs on the island of Elba, in South Africa, in the United States in Maine and South Dakota, and in Manitoba, Canada.

Associated uses of Cesium Atomic clocks Removes air traces in vacuum tubes Ion propulsion systems Medical Photoelectric cells Cesium vapor Magnetometer

Application of Cesium Cesium-based atomic clocks observe

electromagnetic transitions in the hyperfine structure of caesium-133 atoms and use it as a reference point.

Cesium vapor thermionic generators are low-power devices that convert heat energy to electrical energy. In the two-electrode vacuum tube converter, it neutralizes the space charge that builds up near the cathode, and in doing so, it enhances the current flow.

Chemical and Medical use Cesium and mercury were used as a propellant

in early ion engines designed for spacecraft propulsion on very long interplanetary or extraplanetary missions.

Health and safety hazards Exposure to large amounts of cesium

compounds can cause hyperirritability and spasms, but as such amounts would not ordinarily be encountered in natural sources.

Cesium metal is one of the most reactive elements and is highly explosive when it comes in contact with water.

Francium

Fr

Definition of Francium Francium is a chemical element with symbol

Fr and atomic number 87. It was formerly known as eka-cesium and actinium K. It is one of the two least electronegative elements, the other being cesium. Francium is a highly radioactive metal that decays into astatine, radium, and radon. As an alkali metal, it has one valence electron

Francium is vanishingly rare and is found only as very small traces in some uranium minerals. It has never been isolated as the pure element. As it is so radioactive, any amount formed would decompose to other elements.

History of Francium Francium was discovered in 1939 by

Marguerite Perey of the Curie Institute in Paris, (France) but its existence was predicted by Mendeleev during the 1870's. Since its properties should track those of cesium rather closely, he called it eka-cesium. Marguerite Perey noticed an α decay product from actinium, now recognized as Fr. This is the longest-lived isotope of actinium with a half life of about 22 minutes. She called the new element Francium after her country.

Elements in Group IA are called Alkali Metals

Common PropertiesMostly silver coloured metals.So soft, can cut with a knife.Malleable, ductileGood conductorsLow melting and boiling pointsLight weightNot found freely in nature

Elements in Group IA are called Alkali Metals. The alkali metals, found in group 1 of the periodic table

(formerly known as group IA), are very reactive metals that do not occur freely in nature. These metals have only one electron in their outer shell. Therefore, they are ready to lose that one electron in ionic bonding with other elements.

As with all metals, the alkali metals are malleable, ductile, and are good conductors of heat and electricity. The alkali metals are softer than most other metals. Cesium and francium are the most reactive elements in this group. Alkali metals can explode if they are exposed to water. They can all be cut easily with a knife due to their softness, exposing a shiny surface that tarnishes rapidly in air due to oxidation. Because of their high reactivity, they must be stored under oil to prevent reaction with air, and are found naturally only in salts and never as the free element. In the modern IUPAC nomenclature, the alkali metals comprise the group 1 elements, excluding hydrogen (H), which is nominally a group 1 element but not normally considered to be an alkali metal.