Methane is an example of a molecule whose adams are held together by which of the following

Creation of an unnaturally uniform sample to represent a diverse populationcan be avoided by: a. including only willing b. asking another scientist for .c. choosing only identical participants.d. selecting individuals at random.

What conclusion can be made based on the temperature of soil when the light hits the soil at 0°, 45°, and 90° angles in section 2 of the experiment? did your results support your hypothesis? why or why not?

Ihave no idea how to solve these. plus there's another question that is 2) a 10 kilogram meteorite is collected in space and brought back to earth. it is composed of 1.25 kg of uranium-238 and 8.75 kg of lead-206. how many u-238 half lives have passed? what is the approximate age of the meteorite?