This is how platinum appears in the periodic table. A purple box has P t at the center and 78 above. Below it says platinum and below that 195.08. Rounded to the nearest whole number, what is the atomic mass of platinum? 78 117 195 273

3.) 195

Explanation:

Because platinum is 195.079 amu (its on the periodic table)

more info ? ? i don't understand what the question is

explanation:

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.