Why do two isotopes of an element have the same atomic number but different mass numbers?
Why do two isotopes of an element have the same atomic number but different mass numbers?
Isotopes of any given element all contain the same number of protons, so they have the same atomic number (for example, the atomic number of helium is always 2). Isotopes of a given element contain different numbers of neutrons, therefore, different isotopes have different mass numbers.
Will 2 different isotopes of the same element have the same mass number?
Because different isotopes have different numbers of neutrons, they do not all weigh the same or have the same mass. Different isotopes of the same element have the same atomic number. They have the same number of protons. The atomic number is decided by the number of protons.
Why isotopes have same chemical but different physical properties?
This is because isotopes of an element have the same number of electrons as an atom of that element. But they have different number of neutrons which affects the mass number. Mass number determines the physical properties. Hence isotopes have similar chemical properties but different physical properties.
How do different isotopes affect the properties?
The size of an atom also affects some chemical properties. Having a different number of neutrons does not affect either one of these properties, so isotopes of an element will behave (chemically) the same. However, the greater mass of a heavier isotope does provide some useful differences.
Which elements have no isotopes?
In 2 additional cases (bismuth and protactinium), mononuclidic elements occur primordially which are not monoisotopic because the naturally occurring nuclide is radioactive, and thus the element has no stable isotopes at all. For an element to be monoisotopic, it must have one stable nuclide.
Which element does not have a stable isotope?
promethium
Where does carbon 13 come from?
C and 13C are stable, occurring in a natural proportion of approximately 93:1. C is produced by thermal neutrons from cosmic radiation in the upper atmosphere, and is transported down to earth to be absorbed by living biological material.