<span>To calculate the atomic mass of a single atom of an element, add up the mass of protons and neutrons. Example: Find the atomic mass of an isotope of carbon that has 7 neutrons. You can see from the periodic table that carbon has an atomic number of 6, which is its number of protons.</span>
Answer:
Explanation:
there are a certain amount of atoms
Answer;
-Not that reactive
The element found is not very reactive.
Explanation;
-If an element is found in nature in its pure elemental state then the the element found is not very reactive.
-There are many elements which are not much reactive. such as in metals- Ag, Au, Hg, Cu etc. and in Non metals- O2, N2, Inert gases etc.
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For checking its chemical properties you will have to examine it with O2 or C-12.
Element with the same number of shells is element with the same period in periodic table,while element with the same numbers of valence electron is element in the same group .it also have similar chemical properties but different physical properties