Answer: if you examine the rock u might see that it has been in lava before or is dark from burns
Explanation: i dont know if im right but pls mark brainliest
Answer:
D. The chemical formula
Explanation:
For example, in the compound KCl, we know that there are two elements present because you can see it in the chemical formula. We know that KCl consists of potassium and chloride ions.
To rank the effective nuclear charge Z* experienced by a valence electrons of a set of atoms that belong to a same period, you only need to apply the rule of trend: it increases as you move from left to right in the period.
So, lets do it for these atoms: P, Al, Si, Cl
The belong to a same period and the order is Al, Si, P, Cl (just see a periodic table). So the rank is Al < Si < P < Cl
Now, lets do it for these atoms:, Be, Ne, O, C
They belong to the second period. The order is Be, C, O, Ne
So, the rank is Be < C < O < Ne.
