Lesson: Chapter 3 — The Structure of Matter
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Which of these elements has more than one valency?
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Sulphur — its valency is 6 or 2.
Among the first twenty elements, three have two values: phosphorus (5, 3), sulphur (6, 2) and chlorine (7, 1). The rest have one each — sodium 1, calcium 2, aluminium 3.
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