16. Which one is a sublime substance?

1. 1. Table salt

   
   
   

   2. Sugar

   
   
   

   3. Iodine

   
   
   

   4. Potassium Iodide

   
   
   

---

1. View Hint View Answer Discuss in Forum

   Iodine is a sublimate.

   Correct Option: C

   Iodine is a sublimate.

---

17. Food cans are coated with tin and not with zinc because

1. 1. zinc is costlier than tin

   
   
   

   2. zinc has a higher melting point than tin

   
   
   

   3. zinc is more reactive than tin

   
   
   

   4. zinc is less reactive than tin

   
   
   

---

1. View Hint View Answer Discuss in Forum

   zinc is more reactive than tin

   Correct Option: C

   zinc is more reactive than tin

---

---

18. Silicon is used in

1. 1. solar energy devices

   
   
   

   2. semiconductors

   
   
   

   3. transistors

   
   
   

   4. All of these

   
   
   

---

1. View Hint View Answer Discuss in Forum

   All of these

   Correct Option: D

   All of these

---

19. The new strain of bacteria produced by biotechnology in alcohol industry is

1. 1. Escherichia coli

   
   
   

   2. Saccharomyces cerevisiae

   
   
   

   3. Bacillus subtilis

   
   
   

   4. Pseudomonas putida

   
   
   

---

1. View Hint View Answer Discuss in Forum

   Pseudomonas putida

   Correct Option: D

   Pseudomonas putida

---

---

20. Which one of the following elements is used in the manufacture of safety matches?

1. 1. Graphite

   
   
   

   2. Phosphorus

   
   
   

   3. Silicon

   
   
   

   4. Sodium

   
   
   

---

1. View Hint View Answer Discuss in Forum

   The coated end of a match, Known as the match "head" , contains either phosphorus or phosphorus sesquisulfide as the active ingredient and gelatin as a binder.

   Correct Option: B

   The coated end of a match, Known as the match "head" , contains either phosphorus or phosphorus sesquisulfide as the active ingredient and gelatin as a binder.

---