Carbon(C), Phosphorus(P), Sulfur(S) and Selenium(Se)
Well, non metals are a gas at room temperature and so, they were never really a solid in the first place.
No, some like Sulfur and Silicon are Nonmetals and Metalloids respectively.
Nonmetals in the solid state tend to be brittle and poor conductors of heat.
there are only one solid nonmetal: Bromine
Yes, in solid form nonmetals tend to be brittle, however, several nonmetals are gasses and one, bromine, is a liquid.
Nonmetals have high ionization energies and electronegativities. They are usually poor conductors of heat and electricity. Solid nonmetals are generally brittle, with little or no metallic luster. Most nonmetals have the ability to gain electrons easily.
Alloys are solid mixture of metals and some nonmetals as C, O, S, P, B.
Some are solid (eg carbon) some are gaseous (eg oxygen) and one is liquid (bromine).
Most nonmetals are poor conductions of electricity and heat and are reactive with other elements. Solid nonmetals are dull and brittle.
Some examples of nonmetals include oxygen, nytrogen, hydrogen, helium, and neon are a few gases and a few more solid nonmetals include the following; carbon, phosphorus, and sulfur.
Carbon, phosphorus, sulfur, selenium, and iodine
Metals are good conductors of electricity and heat; nonmetals usually aren't. Also, metals tend to have a shiny surface.