What is the half-life of a 100. gram sample of dubnium-261 that decays to 12.5 grams in 86.4 seconds?

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 !

The bone of a dinosaur and the imprint of a leaf are examples of which kind of fossils? a) index b) body c) amber d) trace

What is the volume of 2.5 moles of nitrogen gas (n2)at standard temperature and pressure (stp)?