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:
You need to have a clean surface for contact between the solution and the material.
Explanation:
The presence of impurity on the surface of the material, and lack of surface uniformity (smoothness) can reduce the effective contact between material and solution and can interfere with the electroplating process's success.
Answer:
This means that the wave is bigger because amplitude is the hight of the crest of the wave!
Explanation:
SO IT MEANS THE WAVE IS BIGGER AND TALLER :D
Answer:
Sample A is a pure substance
Sample B is a mixture
Explanation:
We are told that the when the yellow solid, sample A is ground it turned to orange colour and was then dissolved. Some part of the solid settled out at the bottom of the beaker while some part floated on top of the water. 50g of the solid was dissolved and 50.1g of the solid was recovered.
This implies that the substance is pure since the mass dissolved was almost the same mass recovered. The 0.1g addition in mass may result from incomplete drying of the solid.
For sample B, the distillation of the sample of density 0.77 g/ml left a fraction in the beaker with density 1.04 g/ml indicating that the substance is a mixture. Different components of a mixture possess different densities.
