children books

We need to eat food to get the nutrients needed for maintaining a healthy body. Food gives us energy for doing our work, for growing and maintaining other body functions such as digestion, producing body heat and even for breathing. We need food to produce material for the growth and repair of the body and […]

Calcium is a very important mineral that gives us healthy bones and teeth. Apart from this, it helps muscles contract, helps blood clot, controls blood pressure and helps prevent gum disease. Calcium is important for a lot of other body functions in addition to the absorption of vitamins. We lose calcium every day through our

Chemicals are the basic building blocks of all things in this world. Food items consist of chemical compounds that are largely harmless and most often desirable. Nutrients like carbohydrates, proteins, fat and fibre are also chemicals. Most of these nutrients are produced naturally and without any intervention from humans. They contribute in providing us with

A substance dissolves if the attraction between the particles of the solute and the solvent is enough to overcome the attraction of the particles of each substance for the others of the same type. The attraction between ions in table salt and water molecules is enough to pull both individual ions away from the salt

Foam is a dispersion of particles in a continuous medium. The particles are the gas bubbles and the medium is a liquid. When chemical reactions release gas, the chemicals foam up. Just like while baking soda and vinegar are combined, they produce foam. Baking soda releases carbon dioxide that makes carbonic acid when mixed with

Ice floats because it is less dense or has less mass per unit volume than water. Water molecule, due to its strong covalent bonds between the oxygen atom and hydrogen atoms in it, makes it denser than ice. Water reaches its maximum density at 4º C (40º F). As soon as water converts to ice,

By putting salt on the icy roads, the freezing point of water is being altered. Water with higher salinity has a lower freezing point than water that does not have salt. By salting the roads, the freezing point of water that forms ice is lowered, which further results in melting and preventing water, rain or

The two primary factors that control the melting of the snow are the sun’s intensity and air temperature. It melts from the top to the bottom. With the sun’s heat or increase in temperature, the snow crystals start breaking down. With the shift in equilibrium between snow and the cold temperature, there is a change

No air balloon is airtight, which means that the air molecules can escape through the surface or leak through the knot. The surface of the balloon is made of latex rubber, which keeps the air in for some time. However, when the balloon is inflated with air, its skin stretches becoming so thin in some

The Dead Sea is a salt lake that is located at the lowest elevation on land and one of the saltiest lakes on the earth. It is 9 times as salty as the ocean. It is because of its extremely high salinity which makes its water very dense, more than the density of the human

The Dead Sea is a lake. It is 50 kilometres long and 15 kilometres wide. The Jordan river and some small canals drain into it. But no river originates from the Dead Sea. As a result, the water depletes only by evaporation, leaving the salt behind. Moreover, due to its location, it does not receive

Oil lubricates things. A lubricant is a film of liquid that prevents parts from touching, so they slide easily past one another. Lubricants generally work because their molecules bind more tightly to the parts that would otherwise rub together than they do to one another. The oil added to machines sticks to the metal parts,

It is because of the molecules that are present in the food. If we rub our hands in egg-yolk, it will not stain our hands. This is because the egg yolk molecules are very large and do not stick to our hands. However, things like grass, wet paint or food colouring will leave a stain

This is because the Dead Sea is nearly six times as salty as the ocean. It also contains many other dissolved minerals, including magnesium chloride, calcium chloride and potassium chloride in large quantities, in comparison to fresh water in which there are found only minute quantities of these minerals. The high concentration of salt makes

Salt comes from rocks on land. Rainfall contains some dissolved carbon dioxide from the surrounding air. This causes it to be slightly acidic. As the rain erodes the rock, acids in the rainwater break down the rock. This process creates electrically charged atomic particles. These ions are carried through streams and rivers to the ocean.