when elements reacts to form a compound the elements properties changes completely. This happens due to the fact that a chemical reaction has taken place. In a chemical change new substances are formed and the properties of the products differ entirely from that of the reactant.
for example if hydrogen combines with oxygen to form water, the property of hydrogen differs from oxygen and also both differs chemically when compared to water.
To get a submarine to surface, the main vents in the top of the tank are closed and high-pressure compressed air is blown into the ballast tanks, forcing the water out through the flood ports at the bottom of the tank. This increases the vessel's displacement.
The alkali metals would do anything to lose their one electron and become a cation with a plus 1 charge. They basically have the lowest electronegativity values.
