Q21. Which of the following is a non metal that remains liquid at room temperature ?
[A] Chlorine
[B] Bromine
[C] Helium
[D] Phosphorous
Q22. Which compound matches the IR Spectrum?
[A] Trans – 4 – octene
[B] 3 – Hexanol
[C] 1, 5 – hexadiene
[D] None of the above
Q23. In known elements, the maximum number is of
[A] Metalloids
[B] Metals
[C] Non Metals
[D] None of these
Q24. SI unit of equivalent conductance
[A] Siemens m2/equivalent
[B] mho/cm
[C] ohm/cm
[D] Siemens/equivalent
Q25. Hydrogen bomb is based on the principle of
[A] nuclear fusion
[B] nuclear fission
[C] artificial radioactivity
[D] natural radioactivity
Q26. Which one of the following is not a mixture?
[A] cement
[B] milk
[C] air
[D] mercury
Q27. A radioactive substance has a half life of four months, three-fourth of the substance would decay in
[A] 12 months
[B] 8 months
[C] 3 months
[D] 4 months
Q28. The isotopes of chlorine with mass number 35 and 37 exist in the ratio of
[A] 3:1
[B] 1:2
[C] 3:4
[D] 2:3
Q29. The purest form of iron is
[A] nickel steel
[B] steel
[C] wrought iron
[D] pig iron
Q30. Which one of the following elements is the poorest conductor of heat
[A] lead
[B] Sodium
[C] Mercury
[D] zinc