Which of the following is always true about a endothermic reaction? A. The energy of the reactants is greater than the energy of the products B. The energy of the products is greater than the energy of the reactants C. Energy is always released as the chemical reaction proceeds D. All reactants are always compounds never elements

An alcohol thermometer makes use of alcohol's changing in order to measure temperature. as the temperature goes up, the alcohol contained in the thermometer increases in volume, filling more of the thermometer's tube.

To calculate percent by mass, use the equation below: calculate the percent by mass of each element. %n = % %h = % %o = %

The picture represents the process that produces most of the energy used by living organisms on earth. which process is represented in the picture? a) the magnetic attraction between two hydrogen nuclei. b) the fusion of hydrogen nuclei to produce a helium nucleus in the core of the sun. c) the fission of hydrogen nuclei to produce a helium nucleus in the core of the sun. d) the chemical reaction between hydrogen nuclei to produce a helium nucleus in earth's atmosphere.