A 1.5 kg sample of californium-253 (Cf-253) undergoes radioactive decay. After 89 days, 46.875 grams remain. What is the half-life of this isotope? Show your work to earn full credit. Your answer

Classify each statement about effective nuclear charge, zeff, as true or false.

To find the enthalpy of a reaction in the lab, you measured the of the reactants and the change during the reaction.

Need what is special about water as a compound? how does water regulate climate? what drives water evaporation?   why is the water vapor fresh water when it rises from the ocean? why might freshwater in the form of snow take longer to enter the water cycle again than liquid precipitation?   what is an aquifer? what role do people play in the water cycle? plz just answer as many as you can ! thx if you !