During the industrial Czochralski process, ultra-pure single-crystal silicon ingots are grown from molten silicon at temperatures exceeding 1400 ∘C1400\ ^\circ\text{C}1400 ∘C. To prevent the highly reactive molten silicon from reacting, the entire process is conducted under a continuous purge of high-purity argon gas rather than air.
Which statement correctly explains the property of argon that makes it suitable for this process?
Argon has a lower density than air, allowing it to rise and rapidly carry thermal energy away from the molten silicon.
Argon atoms have a stable outer shell of eight electrons (3s23p63s^2 3p^63s23p6), making it chemically inert and preventing oxidation of the molten silicon.
Argon exists as stable diatomic molecules (Ar2\text{Ar}_2Ar2) with a strong covalent bond that prevents dissociation at high temperatures.
Argon has a high electronegativity, which prevents the hot silicon atoms from transferring electrons to it.
44 exam-style questions on Edexcel GCSE Chemistry 7.3 Group 0, covering 7.3.1 The noble gases. Each one has a worked solution and a mark scheme showing where the marks go.