Questions

The four bonds of carbon tetrachloride (CCl4) are polar, but the molecule is nonpolar because the bond polarity is cancelled by the symmetric tetrahedral shape. Hence, making the net dipole as zero and molecule as non-polar.

When other atoms substitute for some of the Cl atoms, the symmetry is broken and the molecule becomes polar.

If the barometer rises, it indicates that good or fair weather is coming and if the falling barometer reading indicates that bad or foul weather is coming. Usually bad weather approaches from the west direction.

The USSR( now a Common Wealth of Independent States) is spread over Europe and Asia

Database provides necessary means to achieve this abstraction. By structure of a database we mean the data types, relations, and constraints that should hold on the data.

Can’t delete a row from primary table if there are related rows in secondary table.

Electric current is measured by the instrument called ammeter. As current in a circuit is measured in amperes, the instrument used is called as ammeter.

A Hole.

When you are digging a hole the more you take out the soil, the igger the hole becomes.