Answer:
5. Selenium, because it does not have a stable, half-filled p subshell and adding an electron does not decrease its stability.
Explanation:
Electron affinity is the amount of energy released when an isolated gaseous atom accepts electron to form the corresponding anion.
Selenium:-
The electronic configuration of the element is:-
![[Ar]3d^{10}4s^24p^4](https://tex.z-dn.net/?f=%5BAr%5D3d%5E%7B10%7D4s%5E24p%5E4)
Arsenic:-
The electronic configuration of the element is:-
![[Ar]3d^{10}4s^24p^3](https://tex.z-dn.net/?f=%5BAr%5D3d%5E%7B10%7D4s%5E24p%5E3)
The 4p orbital in case of arsenic is half filled which makes the element having more stability as compared to selenium.
Thus, selenium has higher electron affinity because adding electron does not decrease the stability as in case of arsenic.
Answer:
2 litres of pure alcohol will be added to make the overall concentration of 9 litres of mixture as 30%.
Explanation:
Suppose x is the number of litres added to the 10% mixture than the quantity of new mixture is given as below
litres
litres
Also the quantity of alcohol is given as
Now the equation is as
So 2 litres of pure alcohol will be added to make the overall concentration of 9 litres of mixture as 30%.
<span>Avogadro's number
represents the number of units in one mole of any substance. This has the value
of 6.022 x 10^23 units / mole. This number can be used to convert the number of
atoms or molecules into number of moles.
163 g Ca (1 mol / 40.08 g) ( </span>6.022 x 10^23 atoms / 1 mol ) = 2.45 x10^24 atoms Ca
Chemical properties can be determined by heat combustion, how they react with other chemicals, Oxidization (lose electrons, losing hydrogen, gaining oxygen), or toxicity.
