Corundum is the hardest mineral in nature after diamond. For this reason it can only be scratched and worked by it. Mohs' hardness scale proves that corundum is indeed a very hard mineral and almost impossible to scratch. This scale states that the corundum has a hardness of 9.0, which indicates that it cannot be scratched by a drill.
Using the same scale, we can find out the hardness of the mineral exposed in the question. The mineral can be scratched by a drill, which means it has a hardness lower than 8.5, and the mineral cannot be scratched by a nail, which indicates that it has a hardness greater than 6.5. Based on this data, we can guarantee that this meniral is softer than the corundum.
The mineral has a hardness greater than 6.5 (steel nail) and less than 8.5 (drill bit). All other choices have a hardness less than 8.5 but corundum has a hardness of 9.0. *Mohs hardness scale
Sodium chloride is an ionic compound. ionic compound is when the compound itself is made up of a metal and non-metal element. thus the answer is potassium bromide and cesium chloride.
<em>In a physical change the appearance or form of the matter changes but the kind of matter in the substance does not. However in a chemical change, the kind of matter changes and at least one new substance with new properties is formed.</em>
<h3>I HOPE THIS WILL HELP YOU IF NOT THEN SORRY HAVE A GREAT DAY:)</h3>
