The mass depends on how many protons and neutrons are in the nucleus. A proton and a neutron are just about the same mass, which is 1.00 amu. The electrons do not affect the mass because their masses are 0.00055 amu each, comparatively little. Practically nothing.
The mass given on the Periodic Table is not in whole numbers though, because it is a weighted average of isotopes of the element. Isotopes are atoms of the same element that have different numbers of neutrons. The weighted average is taken by natural abundance. For instance, if Carbon-12 (six protons, six neutrons) is found 60% of the time, and Carbon-14 (six protons, eight neutrons) is found 40% of the time, then the weighted average is: 12.0*0.60+14.0*0.40=12.8amu
Protons <- it is actually isotopes or quarks or both
The mass of an atom is contained primarily in its nucleus.
An atom is comprised of protons, neutrons, and electrons. The electrons take up the most space as they orbit the nucleus. But nearly all of the mass of the atom is found in the nucleus of the protons and neutrons.
An atom's mass is concentrated in its nucleus, which is located in the center of the atom. Protons and neutrons within the nucleus are responsible for its mass; the electrons, which are located outside of the nucleus, don't contribute to the mass of the atom.
Since a neutron has mass, adding a neutron to an atomic nucleus increases the atom's mass.
When calculating the mass of an atom, you add the mass of the protons and the neutrons. This is the nucleus of the atom. The electrons are small enough to be ignored except in the most delicate calculations.
This depends on the half-life of the atom
The mass of an atom is contained primarily in its nucleus.
It is the nucleus. Mass of electrons is too small
in the nucleus of the atom
That depends entirely on which element it is. for instance, the nucleus of a helium atom would weigh more than the nucleus of a hydrogen atom.
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).
An atom is comprised of protons, neutrons, and electrons. The electrons take up the most space as they orbit the nucleus. But nearly all of the mass of the atom is found in the nucleus of the protons and neutrons.
An atom's mass is concentrated in its nucleus, which is located in the center of the atom. Protons and neutrons within the nucleus are responsible for its mass; the electrons, which are located outside of the nucleus, don't contribute to the mass of the atom.
There are two types of particles in the nucleus of an atom, which are the Protons and the Neutrons. The number of particles in the nucleus depends what is the element. For example, Oxygen has 8 protons and 8 neutrons in the nucleus and Phosphorus has 15 protons and 16 neutrons in the nucleus.
The nucleus of the atom.
Atomic number tells how many protons are inside an atom's nucleus and therefore also how many electrons the atom has. An atom's mass number is the number of protons AND neutrons in the atom's nucleus and this will vary for each isotope of an element.
The vast majority of an atom's mass is within the nucleus; the electrons orbiting the nucleus, which do contain the same amount of charge as the nucleus(albeit negative), have virtually no mass when compared to the nucleus. In fact many scientific disciplines disregard the mass of electrons altogether.