The trend of ionization energy in the periodic table is decreasing from right to left and from top to bottom. In this case, we are given with elements <span>K, Ca, Ge, Se, Br, Kr and see the periodic table to check the trend. The answer from highest to lowest Kr, Br, Se, Ge, Ca, and K</span>
Answer:
3 is the answer.
Explanation:
Nitrogen atoms will form three covalent bonds (also called triple covalent) between two atoms of nitrogen because each nitrogen atom needs three electrons to fill its outermost shell.
<span>The filament of the light bulb will get very hot. This will encourage a chemical reaction with most gases that are surrounding that filament - and the result is that the filament burns out. If the filament is in air, it combines with the carbon of carbon dioxide in the air, and the filament disintegrates. But argon is an inert gas - almost nothing reacts with it. So the filament takes a very long time (theoretically infinity) to burn out. But the bulb cannot contain 100% argon: 99.9% is typical; the remaining 0.1% being air. The bulb manufacturers can control the 'life' of a bulb, based on that principle: they do not want their bulbs to last forever!</span>
Answer: 20.7 kJ
Explanation:
According to first law of thermodynamics:
=Change in internal energy
q = heat absorbed or released
w = work done or by the system
w = work done on the system=
{Work is done on the system is positive as the final volume is lesser than initial volume}
w = 4.51 kcal = 
(1kcal = 4.184kJ)
q = +1.79 kJ {Heat absorbed by the system is positive}
Thus for a system that receives 1.79 kJ of heat from surroundings and has 4.51 kcal of work done on it at the same time is 20.7 kJ
Answer:
Only 
gives spontaneous reaction.
Explanation:
A redox reaction will be spontaneous if standard reduction potential (
) of the reaction is positive. Because it leads to negative standard gibbs free energy change (
), which is a thermodynamic condition for spontaneity of a reaction.
Where 
and 
represents standard reduction potential of reduction half cell and standard reduction potential of oxidation half cell.
(1) Oxidation: 
; 
Reduction: 
; 
So, 
Hence this pair will give spontaneous reaction.
(2) Similarly as above, 
Hence this pair will give non-spontaneous reaction.
(3) Similarly as above, 
Hence this pair will give non-spontaneous reaction.
(4) Similarly as above, 
Hence this pair will give non-spontaneous reaction.
