Explain why burning is a chemical change in wood

In the reading, yao chen-yuan describes traveling to deliver a message. why was he willing to risk danger to travelto tientsin? he wanted to the boxers with their cause

When 13.3 g koh is dissolved in 102.7 g of water in a coffee-cup calorimeter, the temperature rises from 21.4 °c to 31.53 °c. what is the enthalpy change per gram of koh (j/g) dissolved in the water? * take the density of water as 1.00 g/ml. * assume that the solution has a specific heat capacity of 4.18 j/g*k. enter to 1 decimal place. do not forget the appropriate sign /(+). canvas may auto-delete the (+) sign

How many neutrons does an element have if its atomic number is 50 and its mass number is 166