You can experiement with the melting point, boiling point, and freezing point of the elements to prove they have similar properties. This and you can check the different physical and other chemical properties for similarities and comparison.
Because an element is an element and a molecule is a molecule; they are different chemical entities and of course they have different chemical and physical properties.
No; each chemical element has different properties.
An isotope is not a chemical property; rather, it refers to different forms of an element that have the same number of protons but different numbers of neutrons. Isotopes can affect the physical properties of an element, such as its mass and stability, but they do not change its chemical properties.
Isotopes of an element have the same number of protons, which determines the element's chemical properties. The differing number of neutrons in isotopes does not significantly affect the element's chemical behavior.
substance
The differences in chemical properties are not significant (excepting protium and deuterium); the physical properties are different.
an isotope
allotrope
Chemical properties of a element is governed by ELECTRONIC CONFIGURATION of that element. As isotopes of same element have identical electronic configurations, their chemical properties are same.
For the same element, isotopes have equal numbers of protons but different numbers of neutrons. Isotopes of a given element have similar chemical properties due to having the same number of electrons, which determines an element's chemical behavior.
Because the number of protons and electrons are different in each element, which means that their chemical and physical properties are different.
They have similar chemical properties because isotopes of an element have the same number of electrons as an atom of that element. The electron arrangement is the same owing to same chemical properties. However they have different numbers of neutrons, which affects the mass number. Mass number determines the physical properties such as boiling/melting/density etc.