What is the name given to the process where particles settle down on the floor of a chamber?

Identify the negatively charged sol from the following.

On addition of $1 \ mL$ solution of $10\% \ NaCl$ to $10 \ mL$ gold sol in presence of $0.025 \ g$ of starch,the coagulation is just prevented. The gold number of starch is

The critical micelle concentration $(CMC)$ of a soap solution is $5 \times 10^{-4} \ mol \ L^{-1}$. Identify the correct statements about this solution.
$I$. The micelle is stable if the soap solution concentration is $10^{-7} \ mol \ L^{-1}$
$II$. The micelle is stable if the soap solution concentration is higher than $5 \times 10^{-4} \ mol \ L^{-1}$
$III$. Micelles are also known as associated colloids.

The coagulation values in millimoles per litre of the electrolytes used for the coagulation of $As_2S_3$ are given below:
$I$. $(NaCl) = 52,$
$II$. $(BaCl_2) = 0.69,$
$III$. $(MgSO_4) = 0.22$
The correct order of their coagulating power is:

When $FeCl_3$ is added to an excess of hot water,it gives a sol '$X$'. When $FeCl_3$ is added to $NaOH_{(aq)}$ solution,it gives a sol '$Y$'. The sols '$X$' and '$Y$' formed in the above processes respectively are: