An atom of singly ionized magnesium has 12 protons in its nucleus. how many electrons surround this nucleus?

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)

There is a single path for electrons. the current decreases when additional resistors are added. the current will be the same in each resistor. these statements best describe a(n) circuit.

When a spring is compressed, the energy changes from kinetic to potential. which best describes what is causing this change?