Bank PO Questions

The main group number for an element can be found from its column on the periodic table. For example, carbon is in group 4 and has 4 valence electrons. Oxygen is in group 6 and has 6 valence electrons.

Simple covalent compounds are generally named by using prefixes metal name + nonmetal name + suffix –ide to indicate how many atoms of each element are shown in the formula. Also, the ending of the last (most negative) element is changed to -ide. The prefixes used are mono-, di-, tri-, tetra-, penta-, hexa-, and so forth.

Dull means not sharp, not shining, not bright, ...

Hence, the given words are all that means the opposite of dull.

A square and a rectangle each have 4 right (90 deg) angles. 

Both square and rctangle have 4 sides and 4 angles, but the only difference is square is a rectangle with all sides equal.

The support cells of the nervous system are Glia, also called glial cells or neuroglia. In the central nervous system, there are four types of supporting cells. They are ::

* Astrocytes

* Microglial cells

* Ependymal cells

* Oligodendrocytes

In rusting the Iron ore make a chemical reaction with the oxygen in the presence of water and environmental or atmospheric moisture to produce an Iron oxide. Iron oxide is otherwise called as rust.

The rusting of iron is a chemical change because it is two substances reacting together to make a new substance.