The atom's nucleus usually contains at least 99% of the atom's mass. The nucleus is made of protons and neutrons, and outside the nucleus reside the atom's electrons. A proton is about 1,836 times an electron's mass, and a proton's mass is similar to a neutron's mass. Therefore, an atom's electrons barely have any mass at all, compared to that atom's nucleus.
The precise figure varies from element to element and isotope to isotope depending on the number of neutrons in the nucleus, however it is always at least 99.95% which is the ratio between an electron and a proton.
The vast majority of the mass is inside the nucleus.
The exact answer would depend upon which isotope of hydrogen you consider. There are three which contain a different number of neutrons (0, 1 and 2).
However, let's just consider the most common (as it is the most common by a long way; and in any case the difference will be small).
If we work on the basis that an electron is about 1/1836 (an approximation) the mass of a proton then:
The ratio of the mass inside the nucleus to that outside of hydrogen 1 = 1:1/1836 = 1836:1
As a percentage this means the nucleus contains over99.9% of the mass.
As a fraction this is 1836/1837.
It is pretty close to 100%. For hydrogen (atomic number 1), which has the lowest concentration of mass in the nucleus, it is 99.95%. Next is helium (2), with 99.975%. For uranium-238, the heaviest naturally occurring element, the percentage is 99.98% and it remains around there for trans-uranic elements.
It would be almost 100%. Electrons weight only about 1/1836 of a neutron and proton (1 neutron has the same weight as 1 proton), which makes it negligible.
The hydrogen-1 nucleus is the same as the mass of a proton - since it is a proton. The proton's mass is 1.67×10−27 kg. Other nuclei have several times this mass - up to about 250 times the mass of a hydrogen nucleus.
If you mean the nucleus of an atom, different atom have different masses - an uranium atom has more than 200 times the mass of a hydrogen-1 atom (and most of that mass is in the nucleus).
Atoms are normally identified according to the element of which that atom is an example. And that, in turn, is determined by the number of protons in the atom's nucleus. So, any atom that has just one proton is a hydrogen atom. If it has two protons it is a helium atom. And so forth.
the water in which hydrogen atoms have been replaced by deuterium atoms
Ernest Futher Ford
Type your answer here... The hydrogen atoms in heavy water have a neutron in the nucleus, doubling the mass.
Yes, of course: Two thirds of all the atoms (although only a much smaller fraction of the mass) of water are hydrogen atoms.
Almost all of an atom's mass is in the nucleus.
Since a neutron has mass, adding a neutron to an atomic nucleus increases the atom's mass.
The nucleus.
Three-quarters of the Sun's mass is hydrogen. How many hydrogen atoms are in the Sun?
Oxygen atoms weigh more than Hydrogen atoms.
That the mass of a helium nucleus is larger than the mass of the hydrogen nucleus. Also, since the star uses this process to produce energy, that the helium atom has less energy than the original hydrogen atoms - and therefore also less mass.
That the mass of a helium nucleus is larger than the mass of the hydrogen nucleus. Also, since the star uses this process to produce energy, that the helium atom has less energy than the original hydrogen atoms - and therefore also less mass.
The hydrogen-1 nucleus is the same as the mass of a proton - since it is a proton. The proton's mass is 1.67×10−27 kg. Other nuclei have several times this mass - up to about 250 times the mass of a hydrogen nucleus.
Increases it by one mass unit.
the nucleus