Questions

Br-Br.

In Br2, two of the same atoms, pull on each side of the bond is equal making it as non-polar.

The other options all include a significantly more electronegative atom (the oxygens and the chlorine), so those bonds are all polar covalent.

The Early Middle Ages have often been called the Dark Ages, and to some extent  they were truly dark. The people led a miserable life. Education was very uncommon. The helplessness of the comman man the arbitary rule of the king and the barons and the absence of national unity-all these conditions were common in Europe. The term 'Middle Ages' does not cover a uniform period for all the countries of the world.For Europe and the Westren World , the 'Middle Ages' are generally considered to be the period between AD 500 and AD 1500.

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Guglielmo Marconi, an Italian invetor invented Radio in 1890's.