Chemistry Questions

Burning gasoline is the only process that involving in a chemical change in the given options. A chemical change is a change in the starting substances that are called reactants from the formed new substances that are called products. 

There   are five known   states   of matter:    solids,    liquids,    gases, plasma and Bose-Einstein condensates.  The  main  difference in the structures of each state is in the densities of the particles.

Semiconductors are those materials that are neither good conductors nor the good insulators of heat and electricity. Silicon (Si), Germanium (Ge) and Cadmium Sulphide (CdS) are semiconductors which work as conductors in some special conditions only.

Rust is formed from iron and oxygen.

Forms taken up by plants: Mg++ Functions in plants: a part of the chlorophyll molecule -essential in photosynthesis: related to phosphorus metabolism: large quantities found in seed.Mg deficiency symptoms: Mg is mobile, so symptoms occur first in old leaves; A whitish or yellowish striping effect on grasses.