Chemistry

One or more water molecules combine with ionic compounds during bond formation, these are called crystal water.

In oxidation-reduction reaction the element, ion or radical accepts electrons, is called oxidizing agent.

Metal extracted by reduction contains some impurity. The substance that is added to purify it from the impurity is called smelting agent.

The process by which a solid substance melts at the temperature of the melting point is called melting.

Electron configuration is the distribution of electrons in various shells for any element. Such as electron configuration of Al is- Al(13)→1s22s22p63s23p1

Methanal or the saturated aqueous solutions of formaldehyde (40% by volume, 37% by weight) is known as 100% formalin which is mainly used to preserve dead animals. 

In ammonia mole there are 3 bond pair and one lone pair of electron around the nitrogen atom. The lone pair of electron do not make any bond and repulse bond pair so the structure figure of ammonia molecule is triangular pyramid instead of triangular planner.

For conducting electricity the iron or electron need to move. In metal lattice the electron moving freely into the whole metallic part. Atoms turns into ion donating electrons. The ions seemed to be sunk into the electron sea. For these free electrons the electricity conducting power is more for the metal elements.