The mass of a hydrogen atom is 1.67 × 10-24 grams. The mass of a carbon atom is 1.99 × 10-23 grams.
A molecule of methane contains 4 atoms of hydrogen and 1 atom of carbon.
a) Calculate the mass of one molecule of methane
Give your answer in standard form.
b) Calculate the number of molecules in 1 gram of methane.
Give your answer in standard form to 3 significant figures.

Answer this two poles, ab and ed, are fixed to the ground with the of ropes ac and ec, as shown: two right triangles abc and edc have a common vertex c. angle abc and edc are right angles. ab is labeled 13 feet, ac is labeled 15 feet, ec is labeled 10 feet, and ed is labeled 4 feet.what is the approximate distance, in feet, between the two poles? 11.14 feet16.65 feet14.35 feet15.59 feet