The atomic mass of chlorine is 35.45. is it possible for any single atom of chlorine to have a mass number of exactly 35.45? explain

            No, Is it possible for any single atom of chlorine to have a mass number of exactly 35.45.

Average Atomic Mass of Chlorine:

                                                        Naturally Chlorine exists in many isotopes among which only two isotopes are stable. There atomic masses and natural abundance is given as,

            ³⁵Cl  Atomic Mass  =  35 amu

            ³⁵Cl natural Abundance  =  76 %

            ³⁷Cl  Atomic Mass  =  37 amu

            ³⁷Cl natural Abundance  =  24 %

                         Average Atomic Mass  =  (35 × 0.76) + (37 × 0.24)

                         Average Atomic Mass  =  26.6 + 8.88

                         Average Atomic Mass  =  ≈ 35.48

                  Hence, it is cleared that a single Chlorine atom can have a whole number of atomic mass (sum of protons and neutrons). And therefore no single chlorine atom can have an atomic mass in decimals.

alkaline metals are lithium, sodium, rubidium, potassium, cesium and francium.

alkali metals have electronegativity from 0.7 to 1, lowest in periodic table of elements, which means that alkali metals (i group in periodic table) has positive oxidation number in compounds.

electronegativity is a chemical property that describes the tendency of an atom to attract a shared pair of electrons towards itself.

alkaline metals (far left in main group) have lowest ionizations energy and easy remove valence electrons,

for example, potassium is the alkali metal and has a single valence electron in the outer electron shell.

electron configuration of potassium is: ₁₉k 1s²2s²2p⁶3s²3p⁶4s¹.

they can not exist alone in nature, because they are very reactive.

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.