Whic of the following is the least informative property of a mineral. color, luster, streak or cleavage?

All of them are important to identify a mineral and get information from it, but I'd say the least important is cleavage, as it gives you some information, but sometimes it's not definitive information, or you won't be able to get that information.

the answer is true.

this statement is true.

All the elements are arranged by melting points on the periodic table. in row they go from metals to gasses. in the row from sodium to argon, sodium is more reactive than the one on its right, magnesium.