A radioactive isotope has a half-life of 45 minutes. How long would it take for a sample of this isotope to decay to the point where only 10% of the original amount is still there

Calculate the molarity of the solution. 6.02 x 1022 molecules of hci (molecular weight = 36.5 g/mole) in 2.0 liters of water m

Me i dont know what to do! the table compares the number of electrons in two unknown neutral atoms. comparison of electrons atom number of electrons a 10 d 11 use this information to determine the number of valence electrons in the atoms. which of the following correctly compares the stability of the two atoms? both are unreactive. both are highly reactive. a is unreactive and d is reactive. a is reactive and d is unreactive.

The biosphere of the earth is made up of what compound? organic or inorganic?