Question

14. Brass is a

(a) Compound (b) Element (c) Homogeneous mixture (d) Heterogeneous mixture

15. In sugar solution,

(a) Sugar is solute, water is solvent (b) Sugar is solvent, water is solute

(c) Both are solutes (d) Both are solvents.

16. Brass is a solution of molten copper in

(a) solid zinc (b) molten zinc (c) gaseous zinc (d) molten tin

17. Who discovered the electron?

(a) Rutherford (b) Chadwick (c) Thomson (d) Goldstein

18. Which of the following contains maximum number of molecules?

(a) 19g CO2 (b) 1 g N2 (c) 1 g H2 (d) 1 g CH4

19. Which of the following statements is not true about an atom?

(a) Atoms are not able to exist independently.

(b) Atoms are the basic units from which molecules and ions are formed.

(c) Atoms are always neutral in nature.

(d) Atoms aggregate in large numbers to form the matter that we can see, feel or touch.

20. Why was the Thomson’s Model of an atom failed?

i. It could not explain the screening of negative charges from that of positive

ii. It did not tell about the presence of electrons

iii. It did not give an idea about the discrete energy levels

iv. It explained the atom as a whole to be electrically neutral

Choose the correct option from the following:

(a) Only (iii) (b) Both (i) & (iii) (c) Only (i) (d) Both (ii) & (iv)

21. Nanometer is an

(a) Instrument used for measuring micro-distance

(b) Instrument used for measuring macro-distance

(c) Unit for measuring micro-distance

(d) Unit for measuring macro-distance.

22. Barometer measures

(a) Pressure (b) Atmospheric pressure (c) Wind velocity (d) Gaseous pressure.

23. Thermometer is an instrument that measures

(a) Temperature of substance (b) Heat of substance

(c) Radiation of substance (d) Flow energy in a substance.

24. Which of the following correctly represents 360g of water?

(i) 2 moles of water (ii) 20 moles of water

(iii) 6.022 × 1023 molecules of water (iv) 1.2044 × 1025 molecules of water

(a) (i) (b) (i) and (iv) (c) (ii) and (iii) (d) (ii) and (iv)

25. The nucleons are

(a) Protons and electrons (b) Neutrons and electrons (c) Protons and neutrons (d) None

26. The isotope deuterium of hydrogen has

(a) No neutrons and one proton (b) One neutrons and two protons​

Answer 1

Answer:

14.a)

15.b)

16.c)

17.a)

18.b)

19.d)

20. a)

21. b)

22.d)

23.a)

24.b)

25.d)

26.a)