Cathode Ray experiment to figure out electrons exist -> atoms can be broken up into subatomic particles
Answer
No you did not lose weight.
Explanation:
Weight is the force acting on an object, Gravity is a force on earth which does not apply to the moon so your weight may change depending in where you are but your mass will stay the same because mass measures the matter of an object ITSELF! Have a nice day....
Answer:
30, 50
Explanation:
Hello,
In this since an element's atomic number is equal to the number of protons in its atom, we can infer that selenium's atomic number is 30. Moreover, due to the fact the the neutrons are equal to the atomic mass minus the atomic number or the number of protons, by knowing the number of neutrons we compute the atomic as follows:

Thus, answer is 30, 50.
Best regards.
Answer:
No
Explanation:
Protons determine the type of element it is which the number of protons.
Isotopes are determined by the same elements with the same amount of protons, but different number of neutrons.
Stoichiometry is the relationship between the relative quantities of substances taking part in a reaction or forming a compound, typically a ratio of whole integers. Hoped this helped!!!!. Also if you are trying to look for the formulas it should be online just type in stoichometry formulas.