Which one of the following statements is correct?
- ALiquid Sodium is employed as a coolant in nuclear reactorsCorrect
- BCalcium carbonate is an ingredient of toothpaste
- CBordeaux mixture consists of sodium sulphate and lime
- DZinc amalgams are used as a dental filling
Explanation
The correct statement is A.
A) Liquid Sodium is employed as a coolant in nuclear reactors. This statement is correct. Liquid sodium is used as a coolant, particularly in fast breeder reactors, due to its excellent heat transfer properties and low neutron absorption cross-section, allowing it to efficiently remove heat from the reactor core.
B) Calcium carbonate is an ingredient of toothpaste. While calcium carbonate is a common abrasive in many toothpastes, it is not universally used in all toothpastes. Many toothpastes use other abrasives such as hydrated silica. Therefore, while often true, it's not a universally defining characteristic of all toothpastes.
C) Bordeaux mixture consists of sodium sulphate and lime. This statement is incorrect. Bordeaux mixture is a fungicide composed of copper sulfate (not sodium sulfate) and slaked lime (calcium hydroxide).
D) Zinc amalgams are used as a dental filling. This statement is incorrect. Dental fillings primarily use amalgams of mercury with silver, tin, and copper. While zinc can be present in small amounts as a deoxidizer, "zinc amalgams" is not the correct description for the primary type of dental filling.

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