What is the softest mineral on the mohs scale?

Talc. There are ten minerals in Mohs scale, talc, gypsum, calcite, fluorite, apatite, orthoclase, quartz, topaz, corundum, and for last and hardest, diamond.

Compound with sulfer  is bright red 

Both models are effective because they show the valence electrons, and these valence electrons indicate the reactivity of an element.