A new solid, compound Y\mathbf{Y}Y, has been discovered. Scientists investigated the effect of heat on compound Y\mathbf{Y}Y.
Look at the graph. It shows how the state of compound Y\mathbf{Y}Y changes as it is heated.
a.[1]
What is the melting point of compound Y\mathbf{Y}Y?
Meling point=……………………………………………∘C [1] \text{Meling point} = \dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots\dots {^\circ}\text{C [1]} Meling point=……………………………………………∘C [1]b.[1]
A scientist describes compound Y\mathbf{Y}Y 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]c.[1]
Explain how the scientists tell from the graph that compound Y\mathbf{Y}Y 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]d.
[6]
Scientists find out some more information about compound Y\mathbf{Y}Y.
| Property | YES | NO |
|---|---|---|
| High melting point | ✓\checkmark✓ | χ\chiχ |
| Conducts electricity when solid | χ\chiχ | ✓\checkmark✓ |
| Conducts electricity when molten | χ\chiχ | ✓\checkmark✓ |
Describe and explain the type of bonding and structure found in compound Y\mathbf{Y}Y.
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]