In formation of new element why is the resulting element lighter than the components that formed it?

Answer 1

I thought long and hard about your question and it just isn't true. New elements are HEAVIER than the elements they are made from.

You must be referring to something else, because when you say element I am thinking about an element from the periodic table, and all of the man-made elements are heavier than the ones they were made from.

They were made by Alpha partical bombardment, or neutron bombardment, but if you check carefully you'll see each has a high MW than what it was made from.

Answer 2

In nuclear fusion (the process which you are referring to), two lighter elements combine to form a new, heavier, element. For example, the Sun fuses Hydrogen into Helium. In this process, a considerable amount of energy is released. The source of this energy is the difference in the mass of the material going into the process and the mass of the material coming out of the process. A very small amount of matter is converted into energy, thus the new element formed is slightly lighter then the sum of the mass of the material that went into making it. Even though the difference in mass might be miniscule by our, every day, standard, when it is multiplied by the speed of light squared (E = mc^2), even a tiny amount of mass can result in a huge amount of energy.

http://library.thinkquest.org/17940/texts/binding_energy/binding_energy.html

Answer 3

part of the mass is converted into bonding energy