Please help! Geologists determine the hardness of a mineral using the Mohs scale of hardness. Why is it important for geologists to be able to do these tests in the field?

To help determine what type of rock it is

Explanation:

Geologists can use information such as color, hardness, grain size, texture and other aspects of the rock to figure out the classification of a rock. for example, a light blue rock with no visible grain that is translucent and has a hardness of 9 is most likely going to be a saphire. hope this helps

a compound is a molecule made of atoms from different elements.

a. by the combination of an unlimited number of elements

i think it's c. if you look search electronic symbol on google and then click on wiki it shows you a