Atomic Mass accounts for the average mass of all of the different isotopes of an atom of a given element and their relative abundance in nature. Therefore, as the number that appears on the Periodic Table is only an average, there are decimal places included.
The atomic masses of most elements are not whole numbers because they take into account the average mass of all the isotopes of that element, which have different masses due to varying numbers of neutrons. This results in a weighted average that is not a whole number.
Isotopes are atoms with the same number of protons (same atomic number) but different numbers of neutrons, leading to different atomic masses. For example, carbon-12 and carbon-14 are isotopes of carbon with atomic number 6 but atomic masses of 12 and 14 respectively.
The three pairs of elements that are out of order in terms of their atomic masses are iodine and tellurium, cobalt and nickel, and uranium and neptunium. It is necessary to invert their order in the table to maintain the order of increasing atomic masses within each group or period, ensuring that elements with consecutive atomic numbers also have consecutive atomic masses.
Atomic masses of elements are not whole numbers because they take into account the weighted average of the isotopes of that element. Isotopes have different mass numbers, and their relative abundance in nature affects the overall atomic mass calculation. This results in most atomic masses being decimal numbers.
Atoms of the same element that have different masses are called isotopes of the element. The presence of different numbers of neutrons in the nucleus is responsible for the existence of isotopes of an element.
Electrons
Because the masses of protons, neutrons and electrons are not whole numbers.
Most atomic masses on the periodic table are decimal numbers because they are weighted averages of the masses of all isotopes of an element, taking into account their relative abundance. Since isotopes have different masses, the atomic mass is typically not a whole number.
Why are atomic masses of elements not generally whole numbers? The atomic masses listed on the periodic table are a weighted AVERAGE of an element'sisotopes. ... An element's atomic number is the number of protons in its nucleus. Number of protons specifies atom type.
The atomic masses of most elements are not whole numbers because they take into account the average mass of all the isotopes of that element, which have different masses due to varying numbers of neutrons. This results in a weighted average that is not a whole number.
Isotopes describe atoms with different atomic masses due to varying numbers of neutrons.
Atomic numbers increase from left to right across a period on the periodic table. This is because each element in a period has one more proton in its nucleus compared to the element before it. Atomic masses generally increase from left to right as well, but there may be deviations due to isotopes or other factors. Within a group or column, atomic numbers and atomic masses increase from top to bottom as each successive element has more electrons and neutrons than the one above it.
because of its no. in table of elements
Because relitive atomic masses are NEVER whole numbers.
Different numbers of neutrons in their nuclei.
Atoms of the same element that have different atomic masses are called isotopes. Isotopes of an element have the same number of protons but different numbers of neutrons. This results in variations in atomic mass while maintaining the same chemical properties.
If two atoms are isotopes, it means they have the same number of protons but different numbers of neutrons. Thus, they have the same atomic numbers, but different atomic masses.