What is climate ?
. The average weather pattern taken over a long time, say 25 years, is called the climate of the place.
Class 7
Maximum and Minimum Thermometer
There are special thermometers for full day range of temperature, called maximum and minimum thermometers. The maximum temperature of the day occurs generally in the afternoon while the minimum temperature occursgenerally in the early morning. Can you now understand why in summers we feel so miserable in the afternoon andcomparatively comfortable early in the morning?
Effect of The SUN on Weather
All changes in the weather are caused by the sun. The sun is a huge sphere of hot gases at a very high temperature. The distance of the sun from us is very large. Even then the energy sent out by the sun is so huge that it is the source ofall heat and light …
What is weather ?
. The day to-day condition of the atmosphere at a place with respect to the temperature, humidity, rainfall, windspeed, etc., is called the weather at that place . The temperature, humidity, and other factors are called the elements of the weather.
How to measure Rainfall ?
Rainfall is measured by an instrument called the rain gauge. It is basically a measuring cylinder with a funnel on top to collect rainwater
CAUTION of burning magnesium ribbon
It is dangerous to look for long at the burning magnesium ribbon. The teachers should advise children not to stare at the burning ribbon.
Chemical change and Chemical reaction.
A change in which one or more new substances are formed is called a chemical change. A chemical change is also called a chemical reaction. example Carbon dioxide (CO2 ) + Lime water [Ca(OH)2 ] → Calcium Carbonate (CaCO3 ) + Water (H2O)When carbon dioxide is passed through lime water, calcium carbonate is formed, which …
Accompany a chemical change
one or more new substances are produced in a chemical change. In addition to new products,the following may accompany a chemical change:1 Heat, light or any other radiation (ultraviolet, for example) may be given off or absorbed.2 Sound may be produced.3 A change in smell may take place or4 new smell may be given off.5 …
A protective shield
You must have heard of the ozone layer in our atmosphere. It protects us from the harmful ultraviolet radiation which come from the sun. Ozone absorbs this radiation and breaks down to oxygen. Oxygen is different from ozone. Can we call the breaking down of ozone a chemical change?If ultraviolet radiation were not absorbed by …
RUSTING OF IRON
This is one change that affects iron articles and slowly destroys them. Since iron is used in making bridges, ships, cars, truck bodies and many other articles, the monetary loss due to rusting is huge.The process of rusting can be represented by the following equation:Iron (Fe) + Oxygen ( O2 , from the air) water …