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:
radius = 156 pm
Explanation:
The relation between radius and edge length of unit cell of BCC is
r=a
/4
Given
a = 360 pm
Therefore
r = r = radius = 360/4= 155.88 pm
Or
156 pm
Phosphorus is in group 15 meaning it have 5 valence electrons. This means that it needs 3 more electrons to create a full outer shell. As these three electrons are negatively charged it means that P is a 3- ion (it’s an anion [negatively charged ion])
Answer:
0,07448M of phosphate buffer
Explanation:
sodium monohydrogenphosphate (Na₂HP) and sodium dihydrogenphosphate (NaH₂P) react with HCl thus:
Na₂HP + HCl ⇄ NaH₂P + NaCl <em>(1)</em>
NaH₂P + HCl ⇄ H₃P + NaCl <em>(2)</em>
The first endpoint is due the reaction (1), When all phosphate buffer is as NaH₂P form, begins the second reaction. That means that the second endpoint is due the total concentration of phosphate that is obtained thus:
0,01862L of HCl×
= 1,862x10⁻³moles of HCl ≡ moles of phosphate buffer.
The concentration is:
= <em>0,07448M of phosphate buffer</em>
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I hope it helps!
The number of oxygen atoms are 6 atoms
<u><em>Explanation</em></u>
According to the law of mass conservation the number of reactant atoms is equal to number of product atoms.
For given equation to obey the law of mass conservation it need to be balanced as below
4 Al + 3 O₂ → 2 Al₂O₃
Al₂O₃ is the product,therefore the number of oxygen atom
= coefficient in front of Al₂O₃ × subscript of O
=2 x 3 = 6 atoms
