Is weathering a physical or chemical change, and why?

How many moles of air are there in a human lung with a volume of 2.4 l at stp? explain your answer

Consider the following reaction at equilibrium. 2co2 (g) 2co (g) + o2 (g) h° = -514 kj le châtelier's principle predicts that the equilibrium partial pressure of co (g) can be maximized by carrying out the reaction a. at high temperature and high pressure b. at high temperature and low pressure c. at low temperature and low pressure d. at low temperature and high pressure e. in the presence of solid carbon

As changes in energy levels of electrons increase, the frequencies of atomic line spectra they emit