CBSE | NCERT CLASS

Matter In Our Surroundings Solution of NCERT In Text Questions - part-2 Question No: – 7 (a) A gas fills completely the vessel in which it is kept. Explain on the basis of molecular theory. Answer: There is negligible intermolecular force  between particles of gas. As a result, particles of gas move in all directions. Hence, gas particles fill the vessel completely in which it is kept.

Question No: 1 – Among them which are matter? Chair, air, love, smell, hate, almonds, thought, cold, cold-drink, smell of perfume. Answer: - Chair, air, almonds, and cold-drink are matters. Matter: The physical quantities which has mass and occupied space is called matter.

What is matter? Anything which occupies space, has mass and offers resistance to force applied on it is called matter. Example: book, table, water, stone. But love, sad are not matter.

(1) Which of the following expression is a polynomial of one variable? (i) x+5/x+5   (ii) 5 √ x+4x+7   (iii) √ 5x ² +x-5   (iv) x ⁴ +y ² +6

Polynomial : Let x be a variable (literal), n be a positive integer and a ˳ , a ₁ , a ₂ , a ₃ ......a n be constants (real numbers). Then a n xᶯ  + a n-1 . xᶯ⁻¹ + a n-2 . xᶯ⁻² + a₁x + a₀   is known as a polynomial in variable x. We use the notations like f(x), h(x), g(x) to denote polynomial in variable x.

Q1. All animals finally die, yet the species survives. Give reasons for this. Answer : All type of animals during his life span reproduce and produce young ones (offspring). Hence, even after they die, the species still exist on earth.

Q1. Why is it comfortable to lift a school bag with broad straps than thin straps? Answer: Pressure is inversely proportional to area. Since broader straps have greater area, so, the pressure decreases.