Evaluate the following expression to three significant figures:
2^-9 x 4^3

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

The characteristic of two different types of reactions are shown below. reaction a: electrons are gained by the atoms of an element. reaction b: protons are lost by the atom of and element. which statement is true about the atoms of the elements that participate in the two reactions? a: their identity changes in both reaction a and b. b: their identity changes in reaction a but not b. c: their identity changes in reaction b but not a. d: their identity remains the same.

Based on its chemical properties, identify the position of each chemical family on the periodic table.