On addition of $1 \, mL$ of $10 \% \, NaCl$ solution to $10 \, mL$ gold sol in the presence of $0.25 \, g$ of starch,the coagulation is just prevented. The gold number of starch is:

What is the scientific name of modern man?

Planaria possesses high capacity of

Solar radiation emitted by the sun resembles that emitted by a black body at a temperature of $6000\, K$. Maximum intensity is emitted at a wavelength of about $4800\, \mathring{A}$. If the sun was cooled down from $6000\, K$ to $3000\, K$,then the peak intensity would occur at a wavelength of ......... $\mathring{A}$.

Ammonia with excess of $Cl_2$ forms:

If $l_1 = \lim_{x \rightarrow 2^{+}} (x + [x])$,$l_2 = \lim_{x \rightarrow 2^{-}} (2x - [x])$ and $l_3 = \lim_{x \rightarrow \pi / 2} \frac{\cos x}{x - \pi / 2}$,then: