Q1. Which of the following is the most common element in the Universe?
Q2. Indane gas is a mixture of which gases?
(a) butane and hydrogen
(b) butane and propane
(c) butane and oxygen
(d) methane and oxygen
Q3. Alum is used as—
(a) an analgesic
(b) a fertilizer
(c) a purifier for water
(d) a disinfectant
Q4. Which one of the following is the correct sequence of the given elements in the increasing order of their reactivity?
Q5. Silicon is used in which of the following?
(b) solar energy devices
(d) All of these
Q6. Which of the following is the nuclear fuel in the sun?
(d) alpha particles
Q7. Consider the following parts of spectra:
Which of the following is the correct sequence in which the wavelengths increase?
(a) 4, 3, 1, 2
(b) 4, 1, 2, 3
(c) 3, 2, 1, 4
(d) 3, 1, 2, 4
Q8. Cobalt (60) isotope is used in the treatment of which disease?
(a) heart diseases
(d) skin diseases
Q9. A sample of chloroform before using as an anesthetic, is tested by which solution?
(a) Fehling’s solution
(b) Ammonical silver nitrate solution
(c) Ammonical cuprous chloride
(d) Silver nitrate solution after boiling with alcoholic KOH
Q10. The metal constituent of chlorophyll is—
Q11. Which one of the following glasses is used in bullet proof screens?
(a) Reinforced glass
(b) Pyrex glass
(c) Jena glass
(d) Soda glass
Q12. Which one among the following is used as a moderator in nuclear reactors?
(b) Heavy hydrogen
(c) Hydrogen peroxide
(d) Heavy water
Q13. Hydrofluoric acid is not kept in glass bottles because it reacts with—
(a) visible light
(b) silicon dioxide of glass
(c) aluminium oxide of glass
(d) sodium oxide of glass
Q14. The inexhaustible source of energy of the stars is due to—
(a) decay of radioactive elements
(b) conversion of helium to hydrogen
(c) conversion of hydrogen to helium
(d) excess of oxygen that helps burning and release of energy
Q15. Consider the following statements:
Hard water is not suitable for
2. Washing clothes with soap
3. Use in boilers
4. Irrigating crops
Which of these statements are correct?
(a) 1 and 3
(b) 2 and 3
(c) 1, 2 and 4
(d) 1, 2, 3 and 4