Answer : Option DExplaination / Solution:
Cathode rays - In 1897, British physicist J. J. Thomson showed the rays were composed of a previously unknown negatively charged particle, which was later named the electron.
Q10.An
element X has the following isotopic composition 200X = 90 %, 199X
= 8 % and 202X = 2 %. The weighted average atomic mass of the
element X is closest to
Answer : Option DExplaination / Solution:
Total Question/Mark :
Scored Mark :
Mark for Correct Answer : 1
Mark for Wrong Answer : -0.5
Mark for Left Answer : 0