The cleaning action of soap is based on the following principle:(1) Soap dissolves in water to form soap micelles. (2) In water, a sodium soap dissolves to form sodium cations and soap anions. The soap anions have a hydrophobic hydrocarbon chain which is soluble in grease and oil. The hydrophilic end ... Read More

A chemical reaction happens when one or more chemicals (Reactants) are changed into one or more other chemicals (Products). Examples: iron and oxygen combining to make rust.Vinegar and baking soda combining to make sodium acetate, carbon dioxide and water. A decomposition reaction is a type of chemical reaction in which a ... Read More

The difference between rancidity and calcination are as follows: Rancidity Calcination 1. It is a condition in which the substance with oil and fats get oxidized when they are exposed to air.1. It is the conversion of metals into their oxides at high temperature in a limited supply of ... Read More

To do: Find the number which if added to $\frac{-8}{13}$ so we get $24$ Solution: Let’s call this unknown number  $x$ . $ \frac{-8}{13}x=24$ Dividing both sides of this equation by  $\frac{-8}{13}$ , we get:$x=24\div\frac{-8}{13}$ $x=24\times\frac{-13}{8}$ $x=3\times-13$                       [$8\times3=24$] $x= ... Read More

Body Movements- refer to the change in the position of a body part with respect to the whole body, by using muscles to move skeletal parts in relation to the core of the skeleton or in relation to the connection of one bone to another.  These movements are possible only ... Read More

An atom is the smallest unit of matter that constitutes a chemical element. Every solid, liquid, gas, and plasma is composed of atoms. An atom is composed of electrons, protons and neutrons.An element is a pure substance, which is made up of only one kind of atoms. It cannot be further reduced ... Read More

Salt in the ocean is mainly caused by rain washing mineral ions from the land into the water. Carbon dioxide in the air dissolves into rainwater, making it slightly acidic. When rain falls, it weathers the rocks, releasing mineral salts that separate into ions. These ions are carried away by runoff water ... Read More

Reversible Changes are those changes that can be reversed easily to form the 'original substance'. These changes can be transformed back into their original form.Example: ice melts into water and water freezes to form ice.

Pythagoras Theorem: Pythagoras' theorem gives a fundamental relationship among the three sides of a right triangle. It states that the area of the square whose side is the hypotenuse is equal to the sum of the areas of the squares on the other two sides. $a^2 + b^2 = c^2$; a, b ... Read More

Two substance which is soft and opaque is a mattress on the bed, carpets, door mat.