From the reaction between Cu and HNO₃, the formed gas is NO₂ instead of NO₃. Hence the correct balanced equation would be,
Cu(s) + 4HNO₃(aq) → Cu(NO₃)₂(aq) + 2NO₂(g) + 2H₂O<span>(l)
Here, Cu goes to </span>Cu(NO₃)₂ by changing its oxidation number from 0 to +2 while NO₃⁻ goes to NO₂ by reducing its oxidation state from +5 to +4 . Hence Cu is oxidized by HNO₃ in the reaction.
Answer:
Conversion of kinetic energy to potential energy (chemo mechanical energy)
In the state of rest, the rubber is a tangled mass of long chained cross-linked polymer that due to their disorderliness are in a state of increased entropy. By pulling on the polymer, the applied kinetic energy stretches the polymer into straight chains, giving them order and reducing their entropy. The stretched rubber then has energy stored in the form of chemo mechanical energy which is a form of potential energy
Conversion of the stored potential energy in the stretched to kinetic energy
By remaining in a stretched condition, the rubber is in a state of high potential energy, when the force holding the rubber in place is removed, due to the laws of thermodynamics, the polymers in the rubber curls back to their state of "random" tangled mass releasing the stored potential energy in the process and doing work such as moving items placed in the rubber's path of motion such as an object that has weight, w then takes up the kinetic energy 1/2×m×v² which can can result in the flight of the object.
Explanation:
The type of reaction in the example below is a double replacement.
A double replacement can be identified by the switch between two reactants. This can be verified because both a Br and Cl are being switched to a new position in the reaction.
Answer:
Transition from n = 4 to n = 1 corresponds to shortest wavelength.
Explanation:
Process 
A 0.9375
B 0.75
C 0.0421
D 0.1875
According to Rydberg equation for electronic transition in H-like atoms:
where, 
is wavelength of light emitted or absorbed, 
is Rydberg constant.
So, higher the value of 
, lower will the corresponding wavelength of light.
Hence process A will be associated with shortest wavelength.
