Applications & Uses പീരിയോഡിക് ടേബിൾ

The periodic table is not only a chart on the classroom wall. The salt in your kitchen, the chalk on the blackboard and the bleaching powder in the water tank are all made from its elements. So are the neon signboard on the shop, the bell-metal ഓട് nilavilakku, the gold jewellery of Thrissur and the black sand of the Chavara beach. On this page every family മൂലക കുടുംബങ്ങൾ gets a short story, a small animation and a sample exam question.

1. Alkali metals: the salt in the kitchen and the yellow street lamp

You never see pure sodium at home, but you eat it every day. Common salt is sodium chloride, NaCl. Sodium is so reactive that in nature it is always found joined with other elements. The yellow-orange street lamps on many highways are sodium vapour lamps: a little sodium vapour glows when electricity passes through it. Sodium, potassium and the other members of group 1, the alkali metals ആൽക്കലി ലോഹങ്ങൾ, all have just one outermost electron. They give it away easily, which is why they all react in the same lively way. Potassium is needed by plants, so it is in the “K” of the N-P-K fertiliser on a farmer's bag.

2. Alkaline earth metals: bones, chalk and green leaves

Group 2, the alkaline earth metals ആൽക്കലൈൻ എർത്ത് ലോഹങ്ങൾ, are all around you. Calcium makes your bones and teeth strong. Chalk, limestone, marble and sea shells are all calcium carbonate, CaCO₃, the white compound of Table 2.10. In the green colour of every leaf, called chlorophyll, there is a magnesium atom right at the centre of each molecule. Without magnesium, a coconut palm cannot make its food. Calcium (2, 8, 8, 2) and magnesium (2, 8, 2) both have 2 outermost electrons.

3. Groups 13 to 16: vessels, pencils, chips, fertilisers and oxygen

Many of the elements of the main groups പ്രധാനഗ്രൂപ്പ് മൂലകങ്ങൾ are in daily use. Aluminium vessels and foil come from group 13 (boron family). Pencil “lead” is really graphite, a form of carbon, from group 14 (carbon family). Computer chips and solar panels are made of silicon, a metalloid ഉപലോഹങ്ങൾ from the same group. Fertilisers carry nitrogen and phosphorus (group 15, nitrogen family). Hospitals keep oxygen cylinders (group 16, oxygen family). This one corner of the table has metals, non-metals and metalloids side by side, just as the key box says.

4. Halogens: clean water, strong teeth and iodised salt

After the floods, health workers add bleaching powder to wells and water tanks. It releases chlorine, which kills germs. Swimming pools and town water supplies are made safe in the same way. Your toothpaste may say “contains fluoride”: compounds of fluorine help to make tooth enamel harder. The salt packet says “iodised”, which means a tiny amount of an iodine compound is added. Fluorine, chlorine, bromine and iodine are the halogens ഹാലൊജനുകൾ of group 17. Every one of them has 7 outermost electrons.

5. Noble gases: neon signs, argon bulbs and helium balloons

The red-orange glow of a shop's signboard comes from neon in a glass tube. Old filament bulbs are filled with argon. Argon does not react with the white-hot filament, while the oxygen of air would burn it out at once. Welders also use argon to shield hot metal from air. The balloons sold at temple festivals that float up are filled with helium. It is very light and, unlike hydrogen, it cannot catch fire. All of these uses depend on one property: noble gases ഉൽകൃഷ്ട വാതകങ്ങൾ have a stable സ്ഥിരത full outer shell, so they do not normally take part in chemical reactions.

6. Transition metals in Kerala life

The middle block of the table is the busiest in a Kerala home. There is the copper or bell-metal uruli, the nilavilakku lit at dusk, the gold jewellery of the Thrissur shops, the galvanised iron roofing sheets and buckets, and the steel almirah. Two coloured compounds have jobs too. Deep-purple potassium permanganate disinfects wells after floods, and blue copper sulphate, mixed with lime as Bordeaux mixture, is sprayed on arecanut palms against the fungal disease മഹാളി (koleroga). Iron, copper, zinc, manganese, chromium, nickel, silver and gold are all transition elements: all metals, and most of their compounds are coloured.

7. The black sand of Chavara

On the beaches of Chavara and Neendakara in Kollam, the sand has black and golden streaks. These are valuable minerals. The black ilmenite is a compound of iron and titanium. At KMML, Chavara, it is turned into titanium dioxide, the bright white pigment in paints, paper and plastics. The golden monazite contains the rare earths റെയർ എർത്ത്സ്, the lanthanoids ലാൻഥനോയ്ഡുകൾ of the separate row below the table. They are separated at IREL, Chavara, and used in very strong small magnets, as in motors and earphones, and in the glowing colours of screens and lamps. go further

8. Why chemists love the table: it predicts

A table that groups similar elements lets you predict. Mendeleev left gaps and described elements nobody had seen. One of them was “eka-aluminium”, the element just below aluminium. Four years later gallium was found, and its properties matched. The same idea works today. If you know that sodium and potassium are reactive metals with one outer electron, you can say that rubidium, just below them in group 1, will behave the same way, and even more vigorously.

🌐 Explore online – resources hub

Optional: these websites and simulations need the internet and open in a new tab. Everything you need for the exam is already in this guide.

Mendeleev, Moseley and the periodic law

Interactive periodic tables

Periods, groups and element families

Transition elements and coloured compounds

Lanthanoids, actinoids and the new elements

Size of atoms and periodic trends

Elements from Kerala’s beach sands

More to explore