A new solid, compound W\mathbf{W}W, has been synthesized in a materials lab. Scientists investigated the effect of heat on compound W\mathbf{W}W.
Look at the graph. It shows how the state of compound W\mathbf{W}W changes as it is heated.

What is the melting point of compound W\mathbf{W}W?
Melting point=……………………………………………∘C [1] \text{Melting point} = \dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots {^\circ}\text{C [1]} Melting point=……………………………………………∘C [1]A scientist describes compound W\mathbf{W}W as a pure substance.
Explain what scientists mean when they describe compounds as pure.
…………………………………………………………………………………………[1] \dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots [1] …………………………………………………………………………………………[1]Explain how the scientists tell from the graph that compound W\mathbf{W}W is a pure substance.
…………………………………………………………………………………………[1] \dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots [1] …………………………………………………………………………………………[1]Scientists find out some more information about compound W\mathbf{W}W.
| Property | YES | NO |
|---|---|---|
| High melting point | ✓\checkmark✓ | |
| Conducts electricity when solid | ✓\checkmark✓ | |
| Conducts electricity when molten | ✓\checkmark✓ |
Describe and explain the type of bonding and structure found in compound W\mathbf{W}W.
Use all the information above to justify your answer.
………………………………………………………………………………………… \dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots ………………………………………………………………………………………… ………………………………………………………………………………………… \dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots ………………………………………………………………………………………… …………………………………………………………………………………………[6] \dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots [6] …………………………………………………………………………………………[6]