Alexa is teaching students to measure and compare the speed of a pencil as it is dropped from different heights

why is this experiment considered science?

are able to decide what height allowed the pencil to travel the fastest
it involves experimentation and observation of the pencil dropping from different heights
it involves alexa is judgment on what was the fastest speed of the falling pencil

Which statement describes the appearance of a temperature-vs.-time graph? a horizontal line shows that the temperature increases at a constant rate over time. a vertical line shows that the temperature decreases at a constant rate over time. horizontal lines where the temperature is constant during phase changes connect upward-sloping lines where the temperature increases. horizontal lines where the temperature increases are connected by upward-sloping lines where the temperature is constant for each phase.

What is a possible quantum number set for an electron in the 3s orbital of a magnesium atom

For the reaction shown, calculate how many moles of no2 form when each of the following completely reacts. 2n2o5(g)→4no2(g)+o2(g) part a 1.0 mol n2o5 express your answer using two significant figures. nothing mol m o l request answer part b 5.4 mol n2o5 express your answer using two significant figures.