what are the physical properties boron?
['Atomic Symbol: B.', 'Atomic Number: 5.', 'Element Category: Metalloid.', 'Density: 2.08g/cm3.', 'Melting Point: 3769 F (2076 C)', 'Boiling Point: 7101 F (3927 C)', "Moh's Hardness: ~9.5."]