What causes a repeating pattern of day and night? A. The Earth rotates on its axis over 24 hours.
B. The Earth orbits, or revolves, around the sun.
C. The sun changes its position around the Earth.
D. The Earth is facing different parts of the sun as the day goes

Since the gas in your graduated cylinder is a mixture of butane and water vapor, you must determine the partial pressure of the butane, pbutane, alone. to do this, consult a reference and record the partial pressure of the water vapor, pwater, at the temperature you recorded. use the following formula to compute the partial pressure of the butane. pbutane = atmosphere - pwater use the following combined gas law formula and compute the volume that the butane sample will occupy at stp. (hint: convert both temperatures to kelvin.) pbutane x voriginal = pstandard x vfinal troom tstandard use the following ratio and proportion formula to determine the mass of butane needed to occupy a volume of 22.4 l at stp. grams of butane you used “x” grams of butane ml of butane corrected to stp = 22,400 ml compute the theoretical molar mass of butane based on its formula and the atomic masses on the periodic table. compare your experimental results from #3 to the theoretical value of #4, computing a percent error of your findings using this formula: % error = measured value - accepted value x 100 accepted value use the following ratio and proportion formula to determine the mass of butane needed to occupy a volume of 22.4 l at stp. need asap

An alloy contains 66 g of pure zinc. what is the percentage of zinc in the alloy? express your answer to two significant figures and include the appropriate units.

Citric acid has a ph between 1 and 3.  it is considered to be aa. weak acidb. weak basec. strong based. strong acid