$A$ metal is burnt in air and the ash on moistening smells of $NH_3$. The metal is

Which one of the following is an outer orbital complex and exhibits paramagnetic behavior?

Coal tar is the main source of

Which of the following elements constitutes a major impurity in pig iron?

The equation of trajectory of a projectile is $y=10 x-\left(\frac{5}{9}\right) x^2$. If we assume $g=10 \ m/s^2$,the range of the projectile (in metres) is:

If $A_i$ $(i=1, 2, 3, \ldots, n)$ are $n$ independent events with $P(A_i) = \frac{1}{1+i}$ for each $i$, then the probability that none of $A_i$ occurs is