Question

SECTIONS
25. (1) Name and explain two important laws of chemical combination with examples.
(in) What is the difference between an atom of hydrogen and a molecule of hydrogen?
26.01) How do isotopes differ from isobars?
(1) Mention two medicinal uses of isotopes
(iii) Represent the atomic number and mass number of isotopes of chlorine and carbon.
OR
(1) State the two major postulates put forward by Neil's Bohr in order to overcome
the limitations of Rutherford's model.
(11) On the basis of Thomson's model of an atom, explain how the atom is neutral as a whole.
(iii) The atom of an element has 9 protons and 10 neutrons.
(a) What is the atomic number of the element?
(b) How many electrons will it has ?
(iv) What is the mass number of the element.
27. State Newton's third law of motion.
(11) Are the forces mentioned in the law balanced forces? Will they always produce
accelerations of equal magnitude? Why?
(iii) Two objects of masses 100 g and 200 g are moving along the same line and direction
with velocity of 2m/s and 1m/s, respectively. They collide and after
collision, the object of mass 100 g moves at a velocity of 1.67m/s. Determine the velocity
of the second object
OR
(1) A truck starts from rest and rolls down a hill with a constant acceleration. It travels
a distance of 400m in 20s.Find its acceleration. Find the force acting on it
if its mass is 7 metric tonnes (1metric tonne= 1000 kg)
(ii) A child sets a 5 rupee coin on a stiff playing card covering an empty glass
tumbler. He gives the card a sharp horizontal flick with his finger. The card
shoots away. What happens to the coin and why?
-28. () Calculate the potential energy of an object at rest weighing 5 kg when placed
at a height of 5 m above the level of the ground.
Given gravitational constant g = 9.8 ms
(MA 40 W tube light is used for 8 hr/day. Find how much units of
energy is consumed by the tube light in one day?
29. (1) Diagrammatically show the difference between the three types of muscle tissues.
(ii) Give the name of the connective tissue lacking fibres.
OR
(1) Draw a labelled diagram of a neuron.
(1) Name the following-
(a)Tissue that forms the inner lining of our mouth.
(b) Tissue that connects muscle to bone in humans.
30.() List three characteristics which help us to differentiate amphibians to fishes.
(1) Classify the following organisms as cold blooded and warm-blooded animals.
Shark, lizard, sparrow, rohu.​

Answer 1

Answer:

tissue derived from the line of our mouth tissue that connects muscles to bone in humans list three characteristics which help us tu definite Edward two fishes