Mass Number= number of protons (atomic number) + number of neutrons. So as per the question, 36= number of neutrons + 17. Number of neutrons= 36 – 17= 19

Correct Option: B

Mass Number= number of protons (atomic number) + number of neutrons. So as per the question, 36= number of neutrons + 17. Number of neutrons= 36 – 17= 19

A good reducing agent must be able to donate electrons readily. This means that it must not have very much attraction for electrons. Carbon dioxide is just like any other oxide and can be reduced to its respective elements by applied energy. CO₂+C® 2CO.

Correct Option: A

A good reducing agent must be able to donate electrons readily. This means that it must not have very much attraction for electrons. Carbon dioxide is just like any other oxide and can be reduced to its respective elements by applied energy. CO₂+C® 2CO.

The first ionisation energy is the energy required to remove the most loosely held electron from one mole of gaseous atoms to produce 1 mole of gaseous ions each with a charge of 1+. The first first ionisation energy (in KJ per mole) of Hydrogen: around 1200; Helium: about 2500; Lithium: about 500; and Sodium: about 500.

Correct Option: B

The first ionisation energy is the energy required to remove the most loosely held electron from one mole of gaseous atoms to produce 1 mole of gaseous ions each with a charge of 1+. The first first ionisation energy (in KJ per mole) of Hydrogen: around 1200; Helium: about 2500; Lithium: about 500; and Sodium: about 500.

Sodium benzoate is a preservative. It is bacteriostatic and fungistatic under acidic conditions. It is most widely used in acidic foods such as salad dressings (vinegar), carbonated drinks (carbonic acid), jams and fruit juices (citric acid), pickles (vinegar), and condiments. It is also used as a preservative in medicines and cosmetics.

Correct Option: A

Sodium benzoate is a preservative. It is bacteriostatic and fungistatic under acidic conditions. It is most widely used in acidic foods such as salad dressings (vinegar), carbonated drinks (carbonic acid), jams and fruit juices (citric acid), pickles (vinegar), and condiments. It is also used as a preservative in medicines and cosmetics.

Copper is refined by the method of roasting. In the roaster, the copper concentrate is partially oxidised to produce "calcine" and sulfur dioxide gas. In roasting, the ore or ore concentrate is treated with very hot air. This process is generally applied to sulphide minerals.

Correct Option: A

Copper is refined by the method of roasting. In the roaster, the copper concentrate is partially oxidised to produce "calcine" and sulfur dioxide gas. In roasting, the ore or ore concentrate is treated with very hot air. This process is generally applied to sulphide minerals.