The electrons are of such insignificant mass relative to that of the protons and neutrons, therefore we do not count them when calculating Atomic Mass, so the mass = 2 protons + 2 neutrons = mass number 4.
the mass of electrons is negligble the pe rcentage of an atom's mass comes from its protons and neutrons
Almost all of the mass of an atom is in the nucleus. The nucleus is made up of protons and neutrons, with hydrogen-1 as the lone exception because its nucleus has only a proton in it. In other atoms, protons and neutrons are fused together to form that nucleus. The electrons are out in their electron cloud. And we mention the electron because it has only about 1/1836th the mass of a proton. See how it works? A fistful of electrons weigh almost nothing compared to a single proton. The neutron is slightly heavier than a proton, so when neutrons and protons are gathered in any atomic nucleus, it contains most all of the mass of that atom.
The two particles that make up most of the mass of a hydrogen-2 atom are the proton and neutron. The proton has a positive charge and is responsible for defining the element, while the neutron has no charge and helps stabilize the nucleus.
Their are only 2 shells in the hydrogen atom.
Protons and neutrons, the particles that make up atomic nuclei, are the ones responsible for almost all of the mass of an atom. As the electron has less than 1/1800th the mass of a proton, a whole flock of electrons won't significantly change the mass of an atom. We look to the protons and neutrons (called nucleons when they are being considered as components of an atomic nucleus) to contribute to the mass of an atom, and they will be considered when we derive the atom weight of an element.
all atoms have different masses Mass of an atom is due to protons and neutrons present in an atom and number of proton is something that distinguish between atoms, therefore mass of hydrogen is different to the mass number of oxygen, hydrogen's mass is 1 as it has only 1 proton and no neutrons, and oxygen mass's is 16 as it has 8 protons and 8 neutrons.
The mass number is (by definition) the total sum of proton and neutron number in the nucleus of one particular isotope of an element.
Most of the mass in an atom is in the nucleus. The protons and neutrons are about the same weight, 1 amu. The elecrtons are 1/1840 of the mass of an proton. Neutrons are 2000 times heavier than electrons and protons have an equal mass of neutrons
Number of proton = atom numberfor example:Hydrogen has 1 proton and its atom number is also 1Number of neutrons + number of protons = mass numberfor example:Hydrogen have 1 proton and and NO neutrons, so the mass number is 1Helium has 2 protons and and 2 neutrons, so the mass number is 4
Of the common sub-atomic particles, both the proton and the neutron have mass numbers of 1.
Though a hydrogen atom typically has one proton, its mass is not solely determined by the proton. The mass of a hydrogen atom comes from the combination of the proton and an electron. The electron contributes a much smaller amount to the overall mass compared to the proton.
The nucleolus.
The three particles that make up an atom are protons, neutrons and electrons. Protons and neutrons both have a mass of 1 unit, whereas the mass of an electron is 1/1837 of that of a proton or a neutron. Therefore, the electron has the least mass as its mass is considered negligible.
In an atom, there are 3 types of particles: protons, neutrons and electrons.Theoretically, protons and neutrons weight 1 Atomic Mass Unit. An electron weights 1/1836 of an Atomic Mass Unit. Therefore, in an atom, electrons weigh the least.
the mass of electrons is negligble the pe rcentage of an atom's mass comes from its protons and neutrons
If an atom has an atomic mass of 101g and 57 neutrons, then:Atomic Mass = (number of protions) + (number of neutrons) 101 = (X) + (57) or.... (101) - (57) = x 101-57=44 the element that has 44 as its atomic number would be RutheniumAs we know mass of atom is primaril constituted by the neutrons and protons,while the mass of electron is neglegible.Taking mass of proton equal to mass of neutron and both having a unit mass.we can say that mass of an atom is equal to the number of protons and neutrons multiplied with the mass of i proton/neutron.we are given mass of lithium =7=>(no. of neutron + no. of protons)*(mass of 1 proton/neutron)=7=>no. of neutrons + no. of protons *(1)=7=>no. of neutrons=7-no. of protons=>no. of neutrons=7-3 (atomic no=no. of protons)=>no. of neutrons=4
Almost all of the mass of an atom is in the nucleus. The nucleus is made up of protons and neutrons, with hydrogen-1 as the lone exception because its nucleus has only a proton in it. In other atoms, protons and neutrons are fused together to form that nucleus. The electrons are out in their electron cloud. And we mention the electron because it has only about 1/1836th the mass of a proton. See how it works? A fistful of electrons weigh almost nothing compared to a single proton. The neutron is slightly heavier than a proton, so when neutrons and protons are gathered in any atomic nucleus, it contains most all of the mass of that atom.