Anything that has mass and volume is matter. Metals have mass and volume, therefore they are matter.
yes
No, it is a category of matter.
metal
No.
A metal detector will not find vegetable matter.
Protactinium is a solid state of matter. Specifically, it is a dense, silvery-gray metal that is radioactive.
No.
Roentgenium is a solid metal.
Technetium is a solid metal.
Thorium is a solid metal.
Lawrencium is a solid metal.
Calcium is a solid metal.