Answer:
The correct answer is making observations in his experiment. In his cathode ray tube experiment J. J. Thomson proved that the cathode rays are indeed negatively charged particles.
Isotopes are forms of the same elements which contain equal number of protons but different number of nucleus in their nuclei, thus the differ in relative atomic mass but they have same chemical properties. The mass number is the summation of number of proton and number of neutron of an atom. If the mass number is known, then one need to know the number of proton in the atom in order to calculate for the number of neutron.
50 you always use the the top number for protons
Answer:
answer is A. increase in pressure
l think this correct answer