You have been given a sample of an unknown

substance. You find out that it does not

dissolve in water, has a very high melting

point and conducts electricity when molten.

The substance is probably

1. C8H18

2. an ionic compound

3. sodium chloride

4. a covalent compound

At first I thought it would be an ionic compound, but it says that it doesn't dissolve in water so im not too sure about it.

What’s the scientific notation for the number 6,840,000,000

An electron moved from shell n = 2 to shell n = 1. what most likely happened during the transition? a fraction of a photon was added. a photon of energy was absorbed. a fraction of a photon was removed. a photon of energy was released.

Pegmatites are igneous rocks in which the individual minerals are very large. typically, the minerals are all light-colored quartz, feldspar and muscovite. if you were given a black and white photograph of a pegmatite in a quarry (where the rock has been blasted and broken), what physical properties could you use to identify those three minerals in this hypothetical photo? describe each mineral and the specific diagnostic properties. be specific.