Answer:
NaBr
Explanation:
When AgBr is dissolved in water, the following equilibrium is set up in solution;
AgBr(s)⇄Ag^+(aq) + Br^- (aq)
If we dissolve NaBr in the water, a common ion (Br^-) is now introduced into the system. This increases the concentration of Br^- and favours the reverse reaction hence more AgBr is precipitated. This is known as common ion effect.
The atomic number of iron, Fe, is 26. This means it has 26 electrons.
Now, as we write the configuration, we come up to electronic subshell 3p, which is completely filled. So the configuration up till this point is identical to Argon, so we may write:
[Ar], 3d, 4s
After the electrons in the Ar configuration are accommodated, there are 8 electrons left for the 3d and 4s shells. The 4s subshell, when empty, is at a lower level than the 3d level, so it fills first. Two electrons are placed here. Therefore, 3d has 6 electrons in Fe.
Index fossils<span> can be </span>used<span> to help determine the relative age of </span>rock<span> layers. </span>Index fossils<span> are from species that only existed for a short time. </span>Index fossils<span> are found in</span>rock<span> layers. Trilobites and Graptolites are </span><span>index fossils.</span>
Explanation:
Nitric acid reacts with copper according to the reaction: ... 4 HNO3(l) + Cu(s) ==> Cu(NO3)2(s and aq) + 2 NO2(g) + 2 H2O(l) The copper nitrate salt that forms is a deep blue color. The nitrogen dioxide is a maroon vapor.
