Answer:
Gravity pulls all sides equally forming a ball
Its D for the second energy level, but the first energy level is 2.
I search it in the internet so here you go
0.81 moles
Explanation:
cobalt chloride when dissolved in water dissociate into cobalt and chloride ions as shown;
CoCl₂ (s) → [Co²⁺](aq) + 2[Cl⁻] (aq)
The mole ratio between CoCl₂ and [Co²⁺] is 1 ; 1 while the mole ratio between CoCl₂ and [Cl⁻] is 1 : 2
Therefore; 0.27 moles of CoCl₂ will form;
(1 * 0.27) = 0.27 moles of [Co²⁺] ions
(2 * 0.27) = 0.54 moles of [Cl⁻] ions
Total moles of dissociated ions are;
0.27 + 0.54
= 0.81 moles
Na (sodium) and Rb (rubidium) have the most similar chemical properties. They're both Alkali metals, found in the first column of the periodic table.