Why a chemical reaction occurs?

Answer 1

Chemical reactions occur so that atoms gain stability. For example, oxygen will react with carbon because the product, carbon dioxide, has more chemical stability - in other words, each atom shares its electrons to give the other atom(s) in the molecule an electron arrangement of more stability that the one before.

Chemical reactions also occur in one of two circumstances:

a) the reaction is following a fundamental law of nature (enthalpy-its the nature of things to want to use the smallest amount of energy possible, so when a reaction can occur that produces more energy, it will. Also, entropy-its the nature of things to be as disorganized as possible, such as the breaking down or decomposing of material)

b) something forces the reaction (this one is self-explanitory)

Answer 2

Basically it just has to do with how the electrons orbiting the atoms in the molecules prefer to behave. Add: Reactions generally happen in order to cause the electrons to reach a lower, more stable energy state.

Answer 3

Chemical changes happen when the inter-molecular arrangements are changed within a substance by the action of heat, electricity or pressure on it. The new inter-molecular arrangements change the chemical reactivity, properties, state, looks, mass, weight of the substance permanently as chemical changes cannot be reversed.

E.G. :- Sugar (C12H22O11) when heated releases water, sugar charcoal because the heat has converted the hydrogen and oxygen into water and has broken the bonds in between the molecules of carbon, hydrogen and oxygen.

Answer 4

Chemical change happens when something is changed like rusting of iron, burning of paper and more but these is only a tip physical change is a state of matter that do not change for example tearing of paper, evaporation, condensation and more.

Answer 5

because of affinities between particles, i.e. a cation binds with an anion because the cation is positive and the anion is negative

Answer 6

according to difference in electronegativity of elements(+ cation , - anion) , activity of elements

Answer 7

Chemical changes are possible because atoms of the elements react with one another in order to become stable.

Answer 8

A chemical reaction occurs because the two elements have smaller amounts of energy compared to their reactants.

Answer 9

Because it is not energetically prohibited.

This means exothermic reactions happen easily and often happen spontaneously, while endothermic reactions are quite hard to start.