what is the Melting point and boiling point of carbon?

Answer 1

Wikipedia is a great place to find in depth information on all elements in the periodic table. See the link I attached for Carbon.

So looking at that page, and assuming you mean pure Carbon-12 , you can see that, at pressures around 10 MPa:

Melting Point = 4300 - 4700 Kelvin (4027 - 4427 Celsius, 7280 - 8000 F)

Boiling Point = 4000 K (3727 C, 6740 F)

NOTE that boiling points depend on pressure. The melting points can vary with pressure but to a lesser extent. Take a look at the Phase Diagram (plot of Pressure against Temperature with the solid,gas and liquid phases marked) and how the Phase Boundaries change.

Below 10 MPa, Carbon sublimates not melts - that is it goes straight to vapor without passing through a liquid phase. So the figure given above is at a pressure greater than 10 MPa to avoid sublimation.

Answer 2

Carbon Melting Point: 4027–4427 °C

Carbon Boiling Point: 3727 °C

Answer 3

carbon dioxide: no melting no boiling
carbon(diamond): melting:3500 celcius boiling:4827 celcius