Q. Which one of the following statements is correct?
(a) Liquid Sodium is employed as a coolant in nuclear reactors
(b) Calcium carbonate is an ingredient of toothpaste
(c) Bordeaux mixture consists of sodium sulphate and lime
(d) Zinc amalgams are used as a dental filling
Answer:
1, 2 and 4
Notes: A Sodium-cooled Fast Reactor (SFR) is a type of nuclear reactor that utilizes molten sodium metal as the reactor coolant as it allows for a high power density with a low coolant volume. [3] An SFR can achieve a core power density of around 300 MW/m3 compared with Pressurized Water Reactors (PWR) that achieve 100 MW/m3.
Calcium carbonate is an ingredient we've been using in our toothpaste since 1975. It represents a safe and natural choice for providing mild abrasivity in our toothpastes. Some alternatives include hydrated silica gels, hydrated aluminum oxides, magnesium carbonate, phosphate salts and silicates.
Bordeaux mixture is a mixture of copper (II) sulphate and slaked lime used as a fungicide. It is used in vineyards, fruit-farms and gardens to prevent infestations of downy mildew, powdery mildew and other fungi.
Zinc-containing amalgams have a longer life when compared to non-zinc amalgams. Indium reduces creep and increases strength whereas palladium reduces corrosion and tarnish. Surface corrosion fills the amalgam/tooth interface with corrosion products bringing down micro leakage.