Why do scientists say that mostt of the mass of an atom is located in the nucleus?

Answer 1

The masses of protons and neutrons are on the order of 1x10-27 kg. The mass of an electron is on the order of 1x10-30 kg. So protons and neutrons, the particles found in a nucleus, weigh around 1000 times as much as the electrons outside the nucleus. So take helium-4 for example: 2 protons, 2 neutrons, and 2 electrons. Its nucleus is around 2000 times more massive than its two electrons. The term "concentrated" is also worth noting. Atoms are much, much, much bigger than their nuclei. A good analogy I often use for this is that if you put a penny in the middle of Giant's stadium, the atom would be the size of the stadium and the penny would be the size of a nucleus. A more specific example would be that the nucleus of a carbon atom has a radius of around 2x10-15 m, and the radius of a carbon atom is around 8x10-11 m. So the nucleus is 40,000 times smaller than the atom.

Answer 2

Quite simply because the nucleus of an atom consists of two particles, positively charged protons and neutral neutrons. Each is nearly about 1850 X as heavy as an electron. T

The atom is surrounded by a swarm of tiny negatively-charged particles called Electrons, but although there are a great number of these, their collective mass is still nowhere near that of the atom's nucleus.

Answer 3

Because electrons are found orbitting the nucleus andare alot smaller then neutrons and protons, which make up the nucleus.

Answer 4

because an electrons mass is so minute compared to protons and neutrons that the mass is said to be contained in the nucleus

Answer 5

Because the protons and neutrons make up the mass and they are both in the nucleus