Railway Science (Chemistry-Metals , Non-Metals and Alloys)

It is an exothermic reaction.
2Na (s) + 2𝐻₂O → 2NaOH (aq) + 𝐻₂(g).
The resultant is non-colored and basic in nature. Sodium hydroxide solution (pH-14): used to produce soaps, rayon, paper, products that explode, dyes, and petroleum products.

Non-metals are such elements which have 4, 5, 6 and 7 electrons in their outermost shell. Examples are carbon, oxygen chlorine etc. Metals are such elements which have generally 1, 2, 3 valence electrons. Examples are Sodium, Potassium, Copper etc.
The noble gases (the inert gasses and aerogenes) - belong to group 18 of the modern periodic table (helium, neon, argon, krypton, xenon, and radon). Metalloid - a chemical element that exhibits some metal and some nonmetal properties. Example - Boron, germanium, silicon, antimony, arsenic etc.

Some other important Non Metallic Minerals - Limestone, gypsum, coal, dolomite, phosphate, salt, and granite. Metallic Minerals - Iron and steel minerals (Magnetite, hematite, goethite, limonite, siderite), Aluminum minerals (gibbsite, boehmite, diaspore, Bauxite), Copper minerals (chalcopyrite, chalcocite), Zinc minerals (sphalerite), Tungsten minerals (wolframite, scheelite), Silver minerals (native silver, argentite). Tungsten (Very high melting point (3422° Celsius)) is used in making the filament of an incandescent bulb.

Mg (Magnesium), Zn (Zinc), Sn (Tin), Pb (Lead), Fe (Iron), Na (Sodium). Reactivity series - Arrangement of metals in the descending order of their reactivities.
All metals that are found above hydrogen in the activity series liberate H₂ gas upon reacting with dilute HCl or dilute H₂SO₄ . It means that they are more reactive than hydrogen.

Electron gain or loss can give an atom a filled outermost electron shell and make it energetically more stable. Electropositive metals lose electrons from their outermost shell in order to become positively charged. The list of top 5 electropositive elements: Cesium, Rubidium, Potassium, Sodium, Lithium.

The reactivity series of metals (activity series) refers to the arrangement of metals in the descending order of their reactivities. Only 3 Elements are less reactive than Copper, one of them is silver (Ag) and the other two are Gold (Au) and Platinum (Pt) and all remaining are more reactive than copper as per the Reactivity series. The more reactive element can displace the less reactive element from its solution.

Elements with metallic character are placed in alkali metals, alkaline earth metals as well as transition metals. Metallic character is associated with the elements that are metals. Francium (Fr) is the most metallic element and it is radioactive in nature while Cesium (Cs) is the most metallic natural element.

It is a process that leads to chemical change when an electric current is passed through an electrolyte. Metals like Na, Mg, Al, Ca are very reactive. So, they are not available in free state and cannot be obtained from their compounds by simple heating or calcination. Sodium (Na) and magnesium (Mg) metals are produced by the electrolysis of their fused chlorides and Aluminium (Al) is produced by electrolysis of Aluminium oxide in presence of cryolite.

Electrovalent or Ionic Compounds: Formed by the complete transfer of electrons. Properties: high melting and boiling points, hard and brittle, solids at room temperature. Examples: Sodium chloride (table salt) NaCl, lithium carbonate Li₂CO₃ , ammonium phosphate (NH₄)₃ PO₄ etc.

Atomic number 30, discovered by Andreas Marggraf. The arrangement of metals in a series of decreasing order of their tendencies to react is called the Reactivity Series of metal. Therefore, the least reactive metal (Platinum) is placed at the bottom while the highly reactive metal (Potassium) is at the top of this series.