i think that it must reflect red light waves.
Increasing the temperature up to the melting point.
only when a change occurs and a new substance is formed
The correct answer is as follows: One Substance Must Dissolve In Another.
It must melt.
For a substance to be an electrolyte, it must be able to ionize or dissociate into ions in solution. Also, it must conduct electricity in solution due to the presence of these free ions.
All wavelengths of light must be absorbed by the substance for it to appear black. When no light is reflected or transmitted, the substance appears black because no color is perceived by the human eye.
must be reflected
A substance that appears black (in a lighted room) is absorbing all of the visible light that hits it, leaving no visible light to reflect off of it to your eye. So it's absorbing visible light of all wavelengths. (You still don't know what's happening to the infra-red or ultraviolet hitting it. For that, you need to use different detectors.)
must be reflected
For a substance to appear white, all wavelengths of light must be reflected equally and simultaneously. This results in a balanced mixture of all visible colors being reflected off the surface.
A substance that appears black (in a lighted room) is absorbing all of the visible light that hits it, leaving no visible light to reflect off of it to your eye. So it's absorbing visible light of all wavelengths. (You still don't know what's happening to the infra-red or ultraviolet hitting it. For that, you need to use different detectors.)
When a substance appears white, it means that all wavelengths of visible light are being reflected equally by the surface of the substance. This results in a combination of all colors of light reaching our eyes, which our brain interprets as white.
He (or she) must float motionless and unattached to any object or cable.
In order to appear on the periodic table a substance must be an element, consisting of only one type of atom with a given number of protons in its nucleus. This number, called atomic number, is unique to each element.
Increasing the temperature up to the melting point.
only when a change occurs and a new substance is formed
only when a change occurs and a new substance is formed