The two observations you would make about the atoms are
- They are made up largely of empty space
- Their mass is concentrated at the center called a nucleus
These observations were made by Ernest Rutherford in his model of the atom established in 1911, when he performed his gold foil experiment and observed the scattering angle of the alpha particles which led him to conclude that the mass of the atom was concentrated at the center.
Also, that most of the alpha particles also went through the gold foil suggested that the atom was made up basically of empty space.
So,
The two observations you would make about the atoms are
- They are made up largely of empty space
- Their mass is concentrated at the center called a nucleus
Learn more about the atom here:
brainly.com/question/24873449
Look at the atomic number of an element on the periodic table which is the smaller number.
The atomic number shows the number of protons/electrons so the number of protons and electrons are the same.
Whereas the mass number of an element (the other number) is the number of protons + neutrons.
Perspex and polythene are good examples of insulators.
I think the answer is electrons configuration