Reversible changes: The changes which can be brought back to its original form are known as reversible changes. For example, melting of wax and stretching of a rubber band.

Irreversible changes: The changes in which the matter cannot be brought back to its original state are known as irreversible changes. For example, burning of paper changes it into ash and smoke. Paper cannot be obtained back from ash and smoke.

The joint where our neck joins the head is a pivotal joint. It allows us to bend our head forward and backward and turn the head to our right or left. In a pivotal joint a cylindrical bone rotates in a ring. Movement at such a joint is limited to rotation around a central axis. 

Vegetable are rich in _____ and_____

Vitamines and minerials 

सूर्य, दिनकर, दिवाकर, रवि, भास्कर, भानु, दिनेश- इन सभी शब्दों का अर्थ है 'सूरज'

Pinhole Camera

A pinhole camera is a simple camera, without lens, in the shape of a box. One of the sides has a small hole and it produces an inverted image of the outside world at other side.

• The box should be painted black from outside and inside for better clarity.
• The object whose image is to be seen should be in bright light.
• Smaller the hole, sharper the image.
• Temporary Black and White images are formed on the screen if a tracing paper is used. Permanent colored and b & w images can be obtained using photographic films instead of tracing paper.
• In the below diagram, two boxes are placed one inside the other. The image of the outer object is created inverted on the inner box translucent screen.

Saeeda’s mother had been suffering from fever, cough, body pain and joint pain etc. A number of physicians treated her. The quacks forbade her normal food. They also advised her to remain in the closed room. They asked her to avoid both sunshine and fresh air. Their advice did not help her. In fact she needed sunshine and fresh air for good health.

Then people suggested that she should consult a specialist. She was poor. However, she knew that life was more precious than money. So she consulted a specialist. She sold her ornaments also to meet the expenditure on medicines. The specialist examined her. He prescribed effective but costly medicines. He allowed her to eat anything of her taste. He laid most importance on fresh air and sunlight. He advised her to shift in a big room with doors and windows open. He asked her to sit in the sunlight from eight to nine daily.

Some people opposed the specialist’s advice. Saeeda’s mother did not listen to their proposals. She got her bed moved to a bigger room. She desired to sit in the sun on her cot for an hour daily.

Unluckily, it remained cloudy for a few days. She started lamenting and complaining to God.
Saeeda saw a spot of pale sunshine late in the afternoon. The people forbade Saceda’s mother to bask in the sun. They told her that it was too late and chilly. Saeeda requested the departing rays of the sun to come the next day with enough warmth and brightness. The rays gave her the desired promise because her ailing mother needed their help.

Next day the rays were keen to go to the earth early in the morning. After all they had given a word to Saeeda. But the sun said. “It’s our day off again. The road to earth is blocked by the clouds”. The ray who had given its word to Saceda said, “Sir, I can’t stay back …… I’ll pierce the clouds to reach Saeeda’s courtyard.”

The sunrays revolted against the sun to keep their honour. They focused their heat and the clouds scattered. The sunrays reached the earth a bit late. Saeeda’s mother basked in the sun and breathed in fresh air. Her pale face glowed. The doctor’s advice had a magical effect on her. She is fully recovered now.

MS Windows is the most popular operating system for personal computers. It has been designed by Microsoft Corporation, USA hence, the name MS Windows. This operating system provides a very simple, easy but powerful interface to the user as it is extensively graphical (GUI—Graphical User Interface).

 When did the banyan tree become a noisy place?
Ans. The banyan tree became the noisiest place in the garden during the fig season.
In hindi:
बरगद का पेड़ शोर करने वाला स्थान कब बना? 
उत्तर अंजीर के मौसम में बरगद का पेड़ बगीचे में शोर का स्थान बन गया।

The mainland stretches from Latitude 8^o4' North to 37^o6' North and from Longitude 68^o7' East to 97^o25' East. The southernmost point in the Indian Territory, (in Great Nicobar Islands) is the Indira Point (6^o45' North), while Kanya-kumari, is the southernmost point of Indian mainland. Tropic of Cancer crosses the country at 23^o30' North dividing the country into almost two equal parts.

India extends from 8 degrees 4 minute north to 37 degrees 6 minute north latitude and 68 degrees 7 minute east to 97 degrees 25 minute east longitude. Thus, its latitudinal and longitudinal extent is about thirty degree.

The edicts describe in detail Ashoka's view about dhamma, an earnest attempt to solve some of the problems that a complex society faced. According to the edicts, the extent of Buddhist proselytism during this period reached as far as the Mediterranean, and many Buddhist monuments were created. Importance of Asoka's edicts are: They are a main source of information about the reign of Ashoka. These edicts and inscriptions contained instructions on religious matters especially Buddhism. ... Ashoka's edicts also tell us about Ashoka's policy of Dhamma.

 Stereotyping is setting an image about people or things based on certain characteristics or their membership to a particular group. Stereotyping is harmful for the individual and society for the following reasons:

1. We set an image of people belonging to one community and then pass on this impression to others. Thus, this establishes an unbroken chain of unestablished form of lies.

2. This image gets fixed and we start to recognise that group based on the set image. This stops us from appreciating the individual qualities.

Prejudice means to judge others in a negative way or to see them as inferior. People who are prejudiced may criticise the religious beliefs, habits, customs, dressing styles and languages of other people.

1. Write opposites of the following:

(a) Increase in weight

(b) 30 km north

(c) 80 m east

(d) Loss of Rs 700

(e) 100 m above sea level

Solutions:

(a) The opposite of increase in weight is decrease in weight

(b) The opposite of 30 km north is 30 km south

(c) The opposite of 80 m east is 80 m west

(d) The opposite of loss of Rs 700 is gain of Rs 700

(e) The opposite of 100 m above sea level is 100 m below sea level

Click on the given link for ncert solutions:

Integers

• <a href="http://mycbseguide.com/blog/ncert-solutions-class-6-maths-integers-ex-6-1/">Integers Ex-6.1</a>
• <a href="http://mycbseguide.com/blog/ncert-solutions-class-6-maths-integers-ex-6-2/">Integers Ex-6.2</a>
• <a href="http://mycbseguide.com/blog/ncert-solutions-class-6-maths-integers-ex-6-3/">Integers Ex-6.3</a>

Monsoon winds bring rainfall in India. Agriculture in India depends on rains. Good monsoons mean sufficient rain and a good crop. Hence, monsoon winds is very important. Our prosperity depends on these winds.

Inspite of several efforts made by the government inequalities still exist in our society. Even today low caste people are being discriminated against and treated unequally. The reason behind it is that people refuse to think of them as equal even though the law requires it. This attitude of the people is so deeply rooted that it can not change all of a sudden. It will take a lot of time. Even though people are aware that discrimination is against the law, they continue to treat others unequally on the basis of caste and religion. People are also discriminated against on the basis of economic status, disability and gender.
Unless people believe that every person deserves to be treated equally and with dignity, the present attitude cannot be rooted out. Changing people's attitude is a very slow process and hence establishment of equality in society is a continuous struggle.

Inequality and discrimination are the two different concepts. But they are related closely to each other. Inequality may be the difference between caste, creed, culture, language, religion, economic status, educational background etc. Everyone differs from the other in society. Discrimination takes place when one acts against an individual or a community on the basis of difference. A Whim or a prejudice works behind it. If one tries to exploit the other individual who is down in status.
In any way, it is called discrimination. That discriminated individual or community is devoid of the common opportunity or facility provided by the society. It is not at all healthy for a good society.

Some examples of the prevalent stereotypes are as follows:

• Girls are supposed to be soft spoken and submissive in nature. They are supposed to have keen interest in music and painting. They cry too often. They need to learn cooking, doing household chores and tidying up the house.
• Boys are supposed to be aggressive and naughty. They are supposed to have keen interest in adventure sports and outdoor sports. Boys should not cry because crying is a sign of weakness. When a boy becomes adult, he is supposed to earn money to bring the bacon at home.

The untouchables are the persons which are ill-treated and the are called the low castes and Dalits. The many great leaders like Mohandas Gandhi and Dr. B R Ambedkar are fought aginst the untouchability. Ghandiji called them Harijans.