Define enthalpy change. What are the ranges for enthalpy changes for physical, chemical and nuclear reactions?

Oil rich countries in the middle east cover about 4% of earths total land area but prossess about 48% of the worlds known oil reserves what is the main reason for high concentration of reserves in this part of the world

Does the number of ions in solution increase, decrease, or remain constant? it continuously decreases. it continuously increases. it decreases at first, then increases. it increases at first, then decreases.

Which of the following is not an assumption that scientists must make about the natural world? a. regularity b. causality c. predictability d. plausibility