How many protons does an atom with an atomic number of 12 and a mass number of 26 have?

Use the standard enthalpies of formation for the reactants and products to solve for the δhrxn for the following reaction. (the δhf of c2h4 is 52.26 kj/mol, co2 is -393.509 kj/mol, and h2o is -241.818 kj.) c2h4 (g) + 3o2(g) 2co2 (g) + 2h2o(g) δhrxn = the reaction is .

One of the cell membrane's functions is to protect the cell keep wastes in the cell create new cells keep light out of the cell

Describe the difference between a. a hypothesis and a theory and b. an observation and an experiment.