Mass of solute = 25.8 g
mass solution = 212 g
% =( mass of solute / mass solution ) x 100
% = ( 25.8 / 212 ) x 100
% = 0.122 x 100
= 12.2 %
Answer: Atoms contain tiny, negatively charged electrons
Explanation: Thomson's experiments with cathode ray tubes helped him to discover the electron (which Dalton did not know about). Dalton thought that atoms were indivisible particles, and Thomson's discovery of the electron proved the existence of subatomic particles.
J.J. Thomson hypothesized and discovered that the atom was not the smallest unit of matter but that instead there were much smaller units. He discovered "sub-atomic particles" which make up atoms. The sub-atomic particle that Thomson discovered was the electron. He discovered this through a process of experiments testing cathode rays.
