The number of electrons in atoms can change when elements combine to form

a. isotopes
b. molecules
c. compounds

Calculate the change in entropy if br2(l) is converted into gaseous br atoms. s° for br2(l) = 152.2 j/(mol•k) s° for br2(g) = 245.5 j/(mol•k) s° for br(g) = 175.0 j/(mol•k)

What mass of natural gas (ch4) must you burn to emit 276 kj of heat?

What is a number added in front of a formula in order to balance the equation