By the end of this lab, you will see how some materials diffuse through a semipermeable membrane but others do not. the materials that you examine will differ in molecule size. some will be larger and some smaller. formulate an investigative question for this situation
is there a multiple choice
because i dont see letters or numbers
the concentration of carbon dioxide (co2) in earth's atmosphere is approaching 397 ppm (parts per million) by volume as of may 2012 and rose by about 2.0 ppm/yr during 2000â€“2009. this current concentration is substantially higher than the 280 ppm concentration present in preindustrial times, with the increase largely attributed to anthropogenic sources.
the atomic number of an element is the number of protons in the nucleus of an atom of that element.
atoms with the same number of protons, but a different number of neutrons are called isotopes.