The words are English ones and the grammar is mostly correct, but put together in that way the result is nonsense.
Firstly, "physical and chemical isotopes" is meaningless. Isotopes have different physical properties, and may even behave different chemically due to the kinetic isotope effect, but I've never heard anyone refer to a "chemical isotope" or "physical isotope".
For an element to officially be considered "discovered", someone has to have produced an isotope of it and that experiment has to be repeatable. So all known elements have at least one isotope, which is at least one more than "no isotopes".
Some of the higher-mass elements may as yet only have had a single isotope produced, if what you were trying to get at was "no other isotopes". However, this doesn't mean no other isotopes are possible, it just means we haven't made them yet. There's good reason to believe that, in the case of the high-Z actinides, the isotopes we haven't been able to make yet may be more stable than those we have been able to make, because the ones we can make tend to be on the neutron-deficient side and more neutrons would probably have a stablizing effect.
In his time were not known the isotopes and Dalton supposed that all atoms of a chemical element are identical.
Isotopes. They differ in the number of neutrons in the nucleus.
The known weighted-averagemass of all the naturally occurring* isotopes for an element is the atomic mass of the element.____________________*This is not the same as "all the known isotopes", becausemost elements have known isotopes that are not naturally occurring.
The known weighted-averagemass of all the naturally occurring* isotopes for an element is the atomic mass of the element.____________________*This is not the same as "all the known isotopes", becausemost elements have known isotopes that are not naturally occurring.
The known weighted-averagemass of all the naturally occurring* isotopes for an element is the atomic mass of the element.____________________*This is not the same as "all the known isotopes", becausemost elements have known isotopes that are not naturally occurring.
Isotopes are elements that differ in the number of neutrons they have. Isotopes of an element have the same number of protons in their nuclei but different numbers of neutrons, resulting in varying atomic weights.
An atom or element that have different masses are known as isotopes.
No - the lightest element Hydrogen has three known isotopes
they are known as isotopes. Dont ask people to do your homework
Chemical elements have between 3 and 36 isotopes. The element with the smallest number of isotopes, 3, is hydrogen (H). The elements that have the greatest possible number of isotopes, 36, are xenon (Xe) and cesium (Cs).
Iron is an element, and there is only one element called iron (Fe). There are no iron element(s), but if you mean isotopes, then some iron isotopes are stable, and some aren't. No known element is stable in of it's isotopes.
Isotopes