In general, the properties that decrease and increase down a group in the periodic table, respectively, are :

According to molecular orbital theory, which of the following is true with respect to Li₂⁺ and Li₂^$$-$$ ?

Let $${a_1},{a_2},.......,{a_{30}}$$ be an A.P.,

$$S = \sum\limits_{i = 1}^{30} {{a_i}} $$ and $$T = \sum\limits_{i = 1}^{15} {{a_{\left( {2i - 1} \right)}}} $$.

If $$a_5$$ = 27 and S - 2T = 75, then $$a_{10}$$ is equal to :

Let
A = $$\left\{ {\theta \in \left( { - {\pi \over 2},\pi } \right):{{3 + 2i\sin \theta } \over {1 - 2i\sin \theta }}is\,purely\,imaginary} \right\}$$
. Then the sum of the elements in A is :