There are 43.2 g of carbon to 14.4 g of hydrogen in a sample of methane (ch4). what percent of 37.8 g of methane is carbon?

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

we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).