There was this substance we used in a lab and I'm not quite sure what it is. It was a clearish, flaky, solid. It was brittle and insoluable in water. Does anyone know what it could be?

I need more information than that to even tentatively identify it. (Note the correct spelling of insoluble.)

Apparently it smells really bad when you burn it. I don't know if that helps.

Colloidal sulfur is white and flacky. It burns producing sulfur dioxide which isn't pleasant to smell but none of that proves anything.

I have to figure out whether the substance is ionic, covalent, molecular or atomic and all I know is that it is insoluable in water, that it is white and flaky, it has no electrical conductivity in water and it's brittle. I don't know how to go about figuring out what kind of substance it is.

Did you do any more tests on it. Write what you did instead of having us guess what you may have had out of thousands of compounds and with meager information. No electrical conductivity probably means it isn't ionic and that fits with poor solubility in water.

I only did 3 tests. Hardness, conductivity, melting point. Supposedly we are supposed to be able to figure out what type of substance it is from those three tests but I'm still uncertain.

Ionic compounds usually are soluble in water, they usually are brittle, and they usually conduct electricity. Molecular compounds usually don't dissolve in water, they don't conduct electricity, and usually they are soft. But if those three tests are all you have to identify the compound (perhaps you have some choices of compounds), it's easy to make an error BECAUSE some ionic compounds are not soluble and if they don't dissolve there can be no conductivity. And diamonds, for example, are extremely hard but they are the epitome of covalent (networking).

Thanks so much :)

Based on the description you provided, the substance you encountered in the lab seems to be a clearish, flaky solid that is brittle and insoluble in water. While it is difficult to definitively identify the substance without further information or testing, we can narrow down the possibilities based on its characteristics.

Here's how you can try to further determine the identity of the substance:

1. Review the lab experiment: Consider the purpose of the experiment you were conducting in the lab. Think about the compounds and materials you were working with. This can provide clues about the possible identity of the substance.

2. Observe additional properties: Apart from being clearish, flaky, and insoluble in water, try to recall if the substance had any other distinct properties. Was it odorless or did it have a particular smell? Did it exhibit any reactivity when exposed to certain chemicals or heat?

3. Conduct solubility tests: While you mentioned that the substance is insoluble in water, it might be worth trying to dissolve it in other common solvents, such as ethanol, acetone, or mineral spirits. By performing solubility tests, you can narrow down the range of possible substances based on their solubility characteristics.

4. Seek expert assistance: If you are unable to determine the substance on your own, it is always a good idea to seek guidance from your lab instructor, a chemistry professor, or a professional chemist. They can provide further advice, conduct additional tests, or refer to reference materials to help identify the substance accurately.

Remember, when dealing with unfamiliar substances, it is important to practice caution and follow proper safety protocols to prevent any harm or hazards.