Tellurium is an element in Group 16. The most common isotope of tellurium is ¹³⁰Te. Its electronic configuration is [Kr] 4d¹⁰ 5s² 5p⁴.

1. (a)Complete Table 1.1. [Table 1.1][3]
2. (b)Identify the sub-shell in an atom of Te that contains electrons with the lowest energy.[1]
3. (c)Construct an equation to represent the first ionisation energy of Te.[1]
4. (d)(i)The radius of Te ions decreases after each successive ionisation. State two factors that are responsible for the increase in the first six ionisation energies of Te.[2]
5. (d)(ii)Sketch a graph in Fig. 1.1 to show the trend in the first seven ionisation energies of Te. [Figure 1.1][2]
6. (e)Te reacts with F₂ at 150°C to form TeFₓ. Molecules of TeFₓ are octahedral with bond angles of 90°. Explain why TeFₓ is octahedral with bond angles of 90°.[2]
7. (f)(i)TeFₓ reacts with water to form tellurium hydroxide and HF. The oxidation number of tellurium does not change during this reaction. Construct an equation for the reaction of TeFₓ with water.[1]
8. (f)(ii)Name the type of reaction that occurs when TeFₓ reacts with water.[1]

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