There are at least two major approaches to understanding cognitive change during adolescence. One is the constructivist view of cognitive development. Based on the work of Piaget, it takes a quantitative, state-theory approach, hypothesizing that adolescents' cognitive improvement is relatively sudden and drastic.
Atoms bond to form molecules. Two or more atoms may bond with each other to form a molecule. When two hydrogens and an oxygen share electrons via covalent bonds, a water molecule is formed. Chemical reactions occur when two or more atoms bond together to form molecules or when bonded atoms are broken apart. Describe the properties of chemical reactions and compounds. Atoms form chemical bonds with other atoms thereby obtaining the electrons they need to attain a stable electron configuration.
It is the interaction of two or more substances, resulting in chemical changes in them. Chemical reactions take place when some kind of energy is supplied to them. The supplied energy may be in the form of heat, light or mechanical shaking for proper contact between the reactant molecules or electricity.