Dalton was the first scientist to use symbols for elements. Chemical symbols act as a vocabulary of chemical language. Chemical symbols are used to describe chemical changes with clarity and precision. Chemical symbols help in identifying specific elements. Chemical symbols also represent an atom of a particular element. Chemical symbols also signify the atomic mass of an element.
$(a)$ How do symbols help in identifying specific elements?
$(b)$ How do we use symbols in daily life for our convenience?
$(c)$ What values do you find in using symbols?

Identify two crops from the following which provide us carbohydrates for energy requirement:
Black gram,Wheat,Lentil,Rice

Gautam visited a fair along with his classmates. There he found that a hawker was selling balloons filled with helium gas. His teacher told the students that the balloons will rise in the sky and then stop after some distance. Gautam questioned his teacher as to why the balloons would stop. He started arguing with his teacher that the balloons would rise indefinitely. His teacher got irritated with him. Just then,Gautam's friend Avdesh took him aside and explained to him that the teacher was correct. The explanation given by Avdesh satisfied Gautam.
$(a)$ Why will the balloon stop after rising to a certain height?
$(b)$ What values are shown by Avdesh and Gautam?

India is a country where three-fourths of the population is engaged in agriculture. Even though the financial conditions of some farmers allow them to adopt higher-level farming practices and improved agricultural technology,they are hesitant to use $HYV$ seeds with traits such as resistance to diseases and pests,or qualities that would result in higher yields.
$(a)$ What is meant by genetically modified crops?
$(b)$ What are the desired agronomic characters for fodder and cereal crops?
$(c)$ In your opinion,what should be done so that modern agricultural technology is adopted by most farmers?

The government was setting up a school in the village. In the panchayat,Vinod,who had just completed his class $X$,suggested that the children should be taught about different agricultural practices and the use of modern technology in them. The Sarpanch liked the idea and arranged for the same.
$(a)$ Children were taught that wheat cannot be grown in the kharif season. Why?
$(b)$ Mention the desirable agronomic character for cereals.
$(c)$ Do you support the suggestion to the Sarpanch? Mention any two values for which Vinod is worth admiration.

Name the two vitamins which are added in the poultry feed.