In the periodic table, the mass number of an element represents the total number of protons and neutrons in its nucleus. Since protons and neutrons have approximately equal mass, the mass number is a whole number.
To determine the number of elements in the periodic table with odd mass numbers, we need to consider the isotopes of each element. Isotopes are atoms of the same element that have different numbers of neutrons.
Out of the naturally occurring elements in the periodic table, there are 118 elements as of 2023. However, not all of them have isotopes with odd mass numbers.
Elements with even atomic numbers tend to have equal numbers of protons and neutrons in their stable isotopes, resulting in an even mass number. Therefore, the elements with odd mass numbers are those with odd atomic numbers, except for hydrogen (atomic number 1), which only has one isotope.
To determine the number of elements with odd mass numbers, we count the elements with odd atomic numbers, excluding hydrogen.
there are 89 elements with odd atomic numbers (excluding hydrogen). Therefore, the number of elements in the periodic table with odd mass numbers is 89. However, please note that this number may change as new elements are discovered or their isotopes are better understood.