How have levels of carbon dioxide changed in the past 100 years quick

How can you write e method for the experiment of separating sand from water by filtration process? 1-materials 2-steps 3-conclusion also the same for the separating process of water and salt by filtration or distillation. quick because i need to finish my hw

Dumbledore decides to gives a surprise demonstration. he starts with a hydrate of na2co3 which has a mass of 4.31 g before heating. after he heats it he finds the mass of the anhydrous compound is found to be 3.22 g. he asks everyone in class to determine the integer x in the hydrate: na2co3·xh2o; you should do this also. round your answer to the nearest integ

Assume you inhale in about 6 l of air per minute how much nitrogen do you breathe in one minute