Explain why the melting point of magnesium is higher than that of sodium?​

Explanation:

According to electron sea theory magnesium shares two valence electrons in electron sea while sodium shares one suggesting that magnesium has stronger metallic bond than sodium so breaking metallic bond in magnesium will require more energy as compared to breaking metallic bond in sodium and that's why melting point of magnesium is greater than sodium. Similarly aluminium has greater melting point than both sodium and magnesium because it shares three electron in electron sea having much stronger metallic bond with other aluminum atom.

trigonal pyramidal

tetrahedral

trigonal planar

bent

in scientific notation, the value of the  speed of light in a vacuum

  will be written as 2.995 * 10^8. when this value is represented in the form of

  a * 10^b, then, a = 2.995 and b = 8.

the value of the speed of light in a vacuum given above can also be rounded up to approximately 300000000. in this case, the scientific notation will be written as 3 *10^8.