Which of the following is used as an inert electrode in electrolysis? MCQ with Answer and Explanation

Explanation:
Borosilicate glass (e.g., Pyrex) contains boron trioxide (B₂O₃) along with silica, giving it low coefficient of thermal expansion, thus resistant to cracking under temperature changes. Soda-lime glass is ordinary glass, used for bottles, windows. Lead crystal has high refractive index for decorative items. Quartz glass (pure SiO₂) has very high melting point but is expensive. Borosilicate is ideal for beakers, test tubes.

Explanation:
Fossil fuels (coal, petroleum, natural gas) are formed from organic matter deposited in sedimentary layers, subjected to heat and pressure over geological timescales. They are non-renewable because their formation takes millions of years.

Explanation:
Magnesium reacts with hot water or steam to form MgO/Mg(OH)₂ and H₂, but very slowly with cold water (thin layer of insoluble hydroxide inhibits reaction). Sodium, potassium, and calcium react vigorously with cold water. Aluminium, zinc, iron react with steam but not cold water. Reactivity with water follows the series: K, Na, Ca (cold water); Mg, Al, Zn, Fe (steam).