Answer:
Questionnaire
Explanation:
This is an instrument for research usually in the form of questions with multiple choice answers with sole purpose of gathering information from respondents for research.
Answer:

A typical human eye will respond to wavelengths from 390 to 710 nm (in vacuum or air). In terms of frequency this corresponds to a band in the vicinity of 420–790 THz.
Answer: C
Explanation:
Some poly nuclear aromatic hydrocarbons are not carcinogenic in themselves. However, when these are made to interact with living cells, enzymes in the cells could convert the polynuclear aromatic hydrocarbon into a carcinogenic material such as benzo-[a]-pyrene. This can now interact adversely with the deoxyribonucleic acid of living cells leading to genetic mutation, that is, irreversible changes in the genes of organisms.
Number of moles of NO2 = 11.5/(14+16x2) =0.250mol
Mole ratio: 4NO2 to 1O2
Number of moles of O2=0.250/4 =0.0625mol
Mass of O2 produced= 0.0625x32 =2g
Answer: B