True
when a substance is impure, it boils over a range of temperature rather than a specific temperature
The Iron atom lost two electrons to become the Fe2+ ion. This is referred to as oxidation.
Using the law of constant proportions which says that within the same compound, elements exist in fixed ratios.
Therefore; we can use the ratio of total mass to the mass of carbon, to determine the amount of carbon in another sample.
Mass C / Mass CH4 = Mass C / Mass CH4
43.2 g / 57.6 g = Mass C / 37.8 g
Mass C = 37.8 g × 43.2 g / 57.6 g
= 28.35 g
Hence; the percentage of carbon will be;
=(28.35/ 37.8 )× 100%
= 75 %
Thus; 75% of 37.8 g of methane is carbon
Answer:
The correct answer is - may not be typical, and participant burden.
Explanation:
The 24-hour recall is nothing but a retrospective method of diet assessment. In this method, an individual is interviewed about his or her diet consumption during the last 24 hours.
The disadvantages or limitations of this method include the inability of a single day's intake to describe the typical diet, multiple recalls to intake, cost and administration time; participant burden, have to recall to reliably estimate usual intake.
