A chemical reaction is defined as the reaction between two or more substances that produces new substances/compounds.
On the other hand, a nuclear reaction is a reaction that alters the nucleus of a certain atom. This can be done either by splitting the nucleus or by joining this nucleus with another one.
Reaction 1:
Cl₂ + H₂ ............> 2 HCl
This is the combination of two elements to produce a new compound.
Therefore, this reaction is a chemical reaction
Reaction 2:
²₁H + ³₁H .........> ⁴₂H + ¹₀n
This is an alteration in the nucleus of a hydrogen atom by bonding it with another nucleus.
Therefore, this reaction is a nuclear reaction
Hope this helps :)
A straight chain hydrocarbon with the formula C5 H10: has a double C-C bond
Answer : The atom with the same number of neutrons as
is, 
Explanation :
- The given atom is,

Atomic mass number = 12
Atomic number = 6
Atomic number = Number of protons = Number of electrons = 6
Number of neutrons = Atomic mass number - Atomic number = 12 - 6 = 6
Now we have to determine the number of neutrons in the given options.
- In atom,

Atomic mass number = 9
Atomic number = 4
Atomic number = Number of protons = Number of electrons = 4
Number of neutrons = Atomic mass number - Atomic number = 9 - 4 = 5
- In atom,

Atomic mass number = 11
Atomic number = 5
Atomic number = Number of protons = Number of electrons = 5
Number of neutrons = Atomic mass number - Atomic number = 11 - 5 = 6
- In atom,

Atomic mass number = 13
Atomic number = 6
Atomic number = Number of protons = Number of electrons = 6
Number of neutrons = Atomic mass number - Atomic number = 13 - 6 = 7
- In atom,

Atomic mass number = 14
Atomic number = 7
Atomic number = Number of protons = Number of electrons = 7
Number of neutrons = Atomic mass number - Atomic number = 14 - 7 = 7
Therefore, the atom with the same number of neutrons as
is, 