Answer:
Helium is in group 18 of the periodic table. How is helium different from the other elements in this group? = Helium atoms have 2 valence electrons, while atoms of the other elements in the group all have 8 valence electrons.
An emission spectrum will occur when = An electron releases energy and falls back to a lower energy level.
Explanation:
Here is some different pics of a water table. I hope this is what you are looking for :). You can click the pictures to in large them.
Answer:

Explanation:
![\rm MX(s) $\, \rightleftharpoons \,$ M$^{+}$(aq) + $^{-}$(aq); $K_{\text{sp}}$ = [M$^{+}$][X$^{-}$]\\\\\text{$K_{\text{sp}}$ gives us information on}\\\\\boxed{\textbf{ the equilibrium between the solid and its ions in solution}}](https://tex.z-dn.net/?f=%5Crm%20MX%28s%29%20%24%5C%2C%20%5Crightleftharpoons%20%5C%2C%24%20M%24%5E%7B%2B%7D%24%28aq%29%20%2B%20%24%5E%7B-%7D%24%28aq%29%3B%20%24K_%7B%5Ctext%7Bsp%7D%7D%24%20%3D%20%5BM%24%5E%7B%2B%7D%24%5D%5BX%24%5E%7B-%7D%24%5D%5C%5C%5C%5C%5Ctext%7B%24K_%7B%5Ctext%7Bsp%7D%7D%24%20gives%20us%20information%20on%7D%5C%5C%5C%5C%5Cboxed%7B%5Ctextbf%7B%20the%20equilibrium%20between%20the%20solid%20and%20its%20ions%20in%20solution%7D%7D)
It tells us nothing about the amount of precipitate that will form or the temperature at which the equilibrium occurs.
The most common allotropes are:-
White phosphorus
Red phosphorus
The red one is an intermediate phase between white and violent phosphorus.
Possibly wet and unstable