Category: Class 7

Soil pollution

What is soil pollution? The soil pollution is defined as the presence of toxic substances in high amount in soil which is harmful for environment . The soil is polluted because of human activities day by day. The soil pollution contain pollutants and contaminants. The polluted substance are those substance which is responsible for the […]

Soil Properties

The soil contain various components i.e minerals , organic material , air and water .On this combination of components the property of soil is depend .If quality and quantity of components decide the soil property i.e percolation of water through soil , moisture , absorption ,texture ,colour ,pH of soil . 1) Percolation of water […]

Soil Types

The type of soil is depend on the size of soil particle .The rocks gets disintegrated and forms particals which is responsible for the production of type of soil . Sometimes rocks crumbled and form large particles or fine particles .The different type of soil has the different characteristics .The types of soil are as […]

Composition of soil

Soil composition : The soil is a storehouse for all the elements that plants need to grow. It also provides support for plant roots .Soil nourish the plants. But did u all think , how plants get nourished by soil? How soil formed ? The soil contain some elements which make it able to feed […]

Soil profile

What is soil? Did u all know, what’s soil mean ?From where soil comes? How soil form? ’’The soil is the skin of our earth” Yes ; As the forms the surface of land and make up the top layer of earth surface. Soil is the natural resources and are the complex mixture of minerals, […]


Salts are defined as ionic compounds. It consists of positively charged ions (cations) and negatively charged ions (anions). Salts are formed when acid and base reacts with each other. For example salt is formed during neutralization reaction. Example: The most common example of salt is NaCl (Sodium chloride) also known as common salt which is […]


In Neutralization reaction certain amount of acid reacts with certain amount of base. During the neutralization reaction salt and water is formed. For Example: In the following neutralization reaction Hydrochloric acid (HCl) reacts with Sodium hydroxide (NaOH) and forms Sodium chloride (NaCl) salt and Water (H ₂O). Salt (NaOH) is neutral ionic compound. Hydrogen or […]

Element and Symbol

Element: Element can be defined as the matter which can not be split up into simpler substance called as element. Examples : Hydrogen (H) ,Helium (He), Carbon (C) There are 118 elements present in the periodic table which is sorted by their atomic number (Z) . In these 118 elements 92 elements are occur in […]

Light Dispersion

In a rainy season, after rainfall you may have enjoyed scenic beauty in nature, which looks like bow (arc) with multiple colours, what we call it? Rainbow! Isn’t it? Hold the plastic scale/protractor (transparent) or compact disc (CD) the path of sunlight, what do you see?See the picture below, think and relate with the rainbow? […]

Convex Lens

Ever wondered what the lens in your eyes is like? How you can easily see large objects? What is the capacity of magnification of our eye lens? How our eye can produce exact and sharp image of the object? You must have noticed that person who cannot see nearby objects clearly uses spectacles whose glasses […]