Option “C” is correct Baking soda is also known as Sodium bicarbonate. It is a chemical compound with the formula NaHCO3 It is a salt composed of sodium ions and bicarbonate ions. Sodium bicarbonate is a white solid that is crystalline but often appears as a fine powder.
334. Who discovered Nitrogen?
1. Faraday
2. Heisenberg
3. Hooke
4. Rutherford
Option “D” is correct Nitrogen is a chemical element with symbol N and atomic number 7. It was first discovered and isolated by Scottish physician Daniel Rutherford in 1772.
335. Device used for the detection and measurement of all types of radiation (alpha, beta and gamma)-
Option “A” is correct A Geiger counter (Geiger-Muller tube) is a device used for the detection and measurement of all types of radiation alpha, beta and gamma radiation.
336. Which among the following metal is used for galvanization?
1. Zinc
2. Copper
3. Iron
4. Silver
Option “A” is correct Galvanisation is the process of applying a protective zinc coating to iron or steel, to prevent rusting. The most common method is hot dip galvanizing, in which steel sections are submerged in a bath of molten zinc.
Option “A” is correct Dry ice, sometimes referred to as “cardice”, is the solid form of carbon dioxide. It is used primarily as a cooling agent. Its advantages include lower temperature than that of water ice and not leaving any residue. It is useful for preserving frozen foods where mechanical cooling is unavailable.
Option “A” is correct A group of gypsum cement, essentially hemihydrated Calcium Sulphate (CaSO4. 1/2 H2O), a white powder that forms a paste when it is mixed with water and then hardens into a solid used in making a cast, mould and sculpture.
339. Which one of the following pairs is correctly matched?
