Chemistry

4. the central and most important part of an object, movement, or group, forming the basis for its activity and growth.
5. atoms as a source of nuclear energy.
8. level he fixed amount of energy that a system described by quantum mechanics, such as a molecule, atom, electron, or nucleus, can have.
10. the appearance of a mineral surface in terms of its light-reflective qualities

1. a thing that is composed of two or more separate elements; a mixture.
2. the ability of a material to be drawn or plastically deformed without fracture.
3. a material or object that permits an electric current to flow easily
6. a solid material that is typically hard, shiny, malleable, fusible, and ductile, with good electrical and thermal conductivity
7. the property of a material that fractures when subjected to stress but has a little tendency to deform before rupture
9. a stable subatomic particle occurring in all atomic nuclei, with a positive electric charge equal in magnitude to that of an electron, but of opposite sign.