All the alkali metals are silvery, soft, malleable and are good conductors of heat and electricity. They are so soft they can be cut with a butter knife. They are very reactive and have low melting points. The alkali metals react with non-metals and make ionic bonding when they have a reaction. When exposed to water the Alkali metals can explode and release hydrogen. What makes them so reactive is that they all have one electron in their outer shell (valence shell). They form hydroxides that dissolve in water and leave behind an alkaline solution which give the alkali metals their name.