Because it is held together by weak forces so no much energy is needed to break the bond
The answer is; C
The radioisotopes in the interior of the earth are not in pure form and have many embedded impurities and are interspersed. Therefore when a neutron is released by a decaying atom, its chances of hitting another radioisotope atom (to continue the chain reaction) are lower than in a manmade nuclear reactor. This way, the radioactive chain reaction in the earth’s interior is not well sustained.
Answer: 2800 g
Explanation:
According to avogadro's law, 1 mole of every substance weighs equal to molecular mass and contains avogadro's number 
of particles.
Given mass = 5 kg = 5000 g
1 mole of 
produces = 1 mole of 
50 moles of produces =
of
Mass of 
2800 g of is produced from 5.0 kg of limestone.
Mg + 2 HCl ------> MgCl₂ +H₂O
The answer is balanced forces
