First find the oxidation states of the various atoms:
<span>in Cr2O2 2- Cr @ +1; In NH3 N @ +3; in CrO3 Cr @ +3, N2 N @ 0 </span>
<span>Note that N gained electrons, ie, was reduced; Cr was oxidized </span>
<span>Now there is a problem, because B has NH4+ which the problem did not, and is not balanced, showing e- in/out </span>
<span>B.NH4+ → N2 </span>
<span>Which of the following is an oxidation half-reaction? </span>
<span>A.Sn 2+ →Sn 4+ + 2e- </span>
<span>Sn lost electrons so it got oxidized</span>
The answer is letter (B).
K value of water is 1x 10^-14
Answer:
Ionic bond
Explanation:
When Na loses an electron, it becomes positive ion.
When Cl gains an electron, it becomes negative ion.
The electrostatic attraction between these ions is an ionic bond.
Answer:
Wavelength of light in (nm) = 579 nm
Explanation:
At first you find out the amount of energy needed to just eject one electron. This is given by 
this energy is given in question in kj/mole. This is the work function of cesium for each electron is equal to the planc'k einstein equation.
