Why are allergic reactions often
referred to as inappropriate
responses of the immune system?

To find the enthalpy of a reaction in the lab, you measured the of the reactants and the change during the reaction.

What is a substance? a. a physical property of matter b. a chemical property of matter c. an element or compound that cannot be physically separated d. characteristics used to tell the difference between mixtures

Which of the following statements is true? an atom consists of protons, electrons, and neutrons.an atom consists of protons and neutrons.an atom consists of electrons bonded to one another.an atom consists of protons bonded to one another.