| 281. | Which of the following elements is an example of noble gas? |
A. nitrogen | |
B. hydrogen | |
C. chlorine | |
D. helium |
| 282. | What is the reason for the rise of the dough when yeast is added? |
A. rise in temperature | |
B. increase in fluid volume | |
C. increase in the number of yeast cells | |
D. release of carbon dioxide gas |
| 283. | Which one of the following is generally not an air pollutant? |
A. sulfur dioxide | |
B. carbon dioxide | |
C. nitrous oxide | |
D. hydrocarbons |
| 284. | halogen used as an anesthetic |
A. chlorine | |
B. bromine | |
C. iodine | |
D. florin |
| 285. | Plants take up nitrogen in the form of |
A. nightress | |
B. nitrous oxide | |
C. nitrite | |
D. Nitrogen oxide |
| 286. | If the vegetation found on the earth ends, then which gas will be lacking? |
A. Carbon dioxide | |
B. nitrogen | |
C. water vapour | |
D. oxygen |
| 287. | Which of the following is not an inert gas? |
A. helium | |
B. neon | |
C. freon | |
D. geneon |
| 288. | By whom was hydrogen discovered? |
A. charles | |
B. cavendish | |
C. priestley | |
D. boyle |
| 289. | Which element is called stray element in chemistry? |
A. Carbon | |
B. oxygen | |
C. nitrogen | |
D. hydrogen |
| 290. | Which element is the most abundant in the universe |
A. nitrogen | |
B. hydrogen | |
C. oxygen | |
D. silicone |