The freezing point is the temperature at which things freeze.
Oxidation numbers is the right answer
No, you cannot, because both acidic and basic solutions can conduct electric <span>currents.</span>
I don't know what the options were but a material that is very likely going to be challenging to recognize under a microscope as a mixture is a homogeneous mixture. A homogenous mixture is uniform and thus hard to recognize as a mixture. An example is water!