Answer:
5000g
Explanation:
mass= density × volume
Since the unit of density here is g/mL, we need to convert the volume to mL.
1L= 1000mL
4L= 4 ×1000 = 4000 mL
Mass of object
= 1.25 ×4000
= 5000g
I don't know this article, but I do know some major changes: first, the change from the plum pudding model (no nucleus, just electrons) to the gold foil experiment, which had Rutherford shoot alpha particles at a sheet of gold only to find them rebounding, proving the existence of a positively charged mass, i.e a nucleus, in the atom. However, this changed again when Bohr realized that the negatively charged electrons should be attracted to the positively charged center, so that there must be something else inside the nucleus.
By adding together the number of protons and neutrons and multiplying by 1 amu, you can calculate the mass of the atom.
The characteristic of the Bohr model that would best support his observation is this assumption: "The energy of the electron in an orbit is proportional to its distance from the nucleus. The further the electron is from the nucleus, the more energy it has." The discrete, bright, colored lines might represent the electrons and its distance from the nucleus. The lights are caused by the energy it has.