Name the type of nutrient that we get from mustard seeds and linseed.

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?

Fill in the blanks:
$(a)$ $A$ total of . . . . . . nutrients are essential to plants.
$(b)$ . . . . . . and . . . . . . are supplied by air to plants.
$(c)$ . . . . . . is supplied by water to plants.
$(d)$ Soil supplies . . . . . . nutrients to plants.
$(e)$ . . . . . . nutrients are required in large quantities and are called . . . . . . .
$(f)$ . . . . . . nutrients are needed in small quantities for plants and are called . . . . . . .

Define $(i)$ Vermicompost,$(ii)$ Green manure,and $(iii)$ Biofertilizer.

$(a)$ What is composite fish culture system?
$(b)$ Mention one merit and one demerit of this system.

Bakut has a poultry farm. He feeds his birds with a protein and fat-rich diet in large amounts. The birds are in good health,but their egg quality is not good.
$(a)$ What should he do to get good production of eggs?
$(b)$ What should he add in the feed to make the shells of the eggs strong?