D. a and b because same-charged particles repel each other
Answer:
Eletrical
Explanation:
The electric transfers 70% of the input energy to kinetic energy 30% is wasted output energy in the form of thermal energy and sound.
99% sure its false
its arranged by atomic number now i believe
First write the molecular equation with states:
(NH4)2S (aq) + 2AgNO3(aq) → Ag2S (s) + 2NH4NO3
Now write a full ionic equation by separating into ions all substances that dissociate: anything (s) (g) or (l) does not dissociate
2NH4 + (aq) + S 2-(aq) + 2Ag+ (aq) + 2NO3- (aq) → Ag2S(s) + 2NH4 + (aq) + 2NO3- (aq)
To write the NET IONIC equation, inspect the full ionic equation above and delete anything that appears on both sides of the → sign:
Net ionic equation:
S 2-(aq) + 2Ag + (aq) → Ag2S(s)
Answer : The energy of the photon emitted is, -12.1 eV
Explanation :
First we have to calculate the 
orbit of hydrogen atom.
Formula used :
where,
= energy of 
orbit
n = number of orbit
Z = atomic number of hydrogen atom = 1
Energy of n = 1 in an hydrogen atom:
Energy of n = 2 in an hydrogen atom:
Energy change transition from n = 1 to n = 3 occurs.
Let energy change be E.
The negative sign indicates that energy of the photon emitted.
Thus, the energy of the photon emitted is, -12.1 eV
