a pure compound because an element is untouched and is just itself
I think it’s C atomic radius and numbers of unshielded protons
The nuclei of atoms become unstable when the repelling forces of the protons cannot be balanced by the number of neutrons in the nucleus. It then re-arranges itself randomly to a more stable configuration by emitting any of a series of particles. During radioactive decay, an atom does not collapse.
Since an atom is mostly empty space - that is it’s nucleus is relatively distant from the electron shells so, in the presence of extreme forces such as gravity inthe collapse of a large star, the inward pressures on the atom overcome the natural balance of the atomic structure and the ‘empty space’ disappears as nuclei are mashed together by the intense pressures and a neutron star is formed. Under even more external pressure, even the neutron star can collapse to form a black hole.
Answer:
2
Explanation:
In two reactions energy is released.
1) C₆H₁₂O₆ + 6O₂ → 6H₂O + 6CO₂ + heat
It is cellular respiration reaction.It involves the breakdown of glucose molecule in the presence of oxygen to yield large amount of energy. Water and carbon dioxide are also produced as a byproduct.
Glucose + oxygen → carbon dioxide + water + 38ATP
2) 2H₂ + O₂ → 2H₂O ΔH = -486 kj/mol
The given reaction is formation of water. In this reaction oxygen and hydrogen react to form water and 486 kj/mol is also released.
The reaction in which heat is released is called exothermic reaction.
Exothermic reaction:
The type of reactions in which energy is released are called exothermic reactions.
In this type of reaction energy needed to break the bonds are less than the energy released during the bond formation.
For example:
Chemical equation:
C + O₂ → CO₂
ΔH = -393 Kj/mol
it can be written as,
C + O₂ → CO₂ + 393 Kj/mol
Endothermic reactions:
The type of reactions in which energy is absorbed are called endothermic reactions.
In this type of reaction energy needed to break the bond are higher than the energy released during bond formation.
For example:
C + H₂O → CO + H₂
ΔH = +131 kj/mol
it can be written as,
C + H₂O + 131 kj/mol → CO + H₂
