Answer:
the proton and the neutron
Explanation:
mass of The proton is approximately 1.6726 × 10^-27 Kg
mass of the electron is approximately 9.109 × 10^-31 Kg
mass of the neutron is approximately 1.6749 × 10^-27 Kg
Here we see that mass of proton and neutron is approximately similar.
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Lets see what is the mass of these particle IN atm unit
mass of these particles can also be described in form of amu(atomic mass unit)
1 atm is the mass defined as 1/12 th of mass of the carbon-12(c-12) atom.
In terms of unit atm
mass of proton = 1 amu
mass of electron = 5.45 × 10−4 amu
mass of neutron = 1 amu
hence we can say that mass of proton = mass of neutron.
mass of atom is sum of mass of all the neutron and proton in the atom.
Hence, mass of neturon and atom cannot be equal.
This makes option four the neutron and the atom , the wrong choice.
correct answer is the proton and the neutron
therefore, An atom contains one proton , one electron and one neutron then, mass of proton is similar in mass of neutron.
This means a release of free energy from the system corresponds to a negative change in free energy, but to a positive change for the surroundings.
Chemical reactions that release energy will not occur without a source of energy. So the answer is release.
Answer: Energy of reactants = 30, Energy of products = 10
Exothermic
Activation energy for forward reaction is 10.
Explanation:
Exothermic reactions are defined as the reactions in which energy of the product is lesser than the energy of the reactants. The total energy is released in the form of heat and 
for the reaction comes out to be negative.
Energy of reactants = 30
Energy of products = 10
Thus as energy of the product < energy of the reactant, the reaction is exothermic.
Activation energy 
is the extra energy that must be supplied to reactants in order to cross the energy barrier and thus convert to products.
for forward reaction is (40-30) = 10.
