Which metal ? Some may be, depending on thickness and type of metal.
No it can't.
Sodium. With a dull knife.
All Gr 1 metals down to Caesium ( which is actually a liquid at room temperature).
That is: Li , Na, K, Rb and Cs.
Sodium can be. But don't try it burns vigorously in air
Li ,Na .K,Rb, are light metals and can be cut with knife very easily .
Cs is liquid at room temperature
It does depend on the metal. As Trevor H (above) says, all group 1 metals can be cut easily. there are others. It is as well to bear in mind that metals are elements which have loose outer electrons which allow them to conduct electricity. They are named metals because of their electrical properties rather than their physical properties. Some are hard (eg tungsten), some are soft (eg gold, lead) and some so soft that they can be cut with a knife.
Yeah typical of the alkali metals only one electron is contributed per atom.leading to a subsequently weaker force of attraction between the electron cloud and the nucleus. Hence metals like sodium can be cut with a knife