Answer:

Explanation:
Hello there!
In this case, according to the given information, it turns out firstly necessary to write out the described chemical reaction as shown below:

Now, we set up the expression for the calculation of the standard free energy change, considering the free energy of formation of each species, specially those of H2 and F2 which are both 0 because they are pure elements:

Regards!
Friction is the force that slows down a ball, if their were no friction, it would not stop.
Answer: friction
Answer:
See explanation
Explanation:
Electron affinity is the energy released when an extra electron is added to a neutral gaseous atom. A negative value of electron affinity indicates that energy is given out and vice versa.
Metals have positive electron affinity since electrons rarely accept electrons, so;
Na(g)+ 1e^- → Na^-(g) positive
Mg(g)+1e^- → Mg^-(g) positive
For the last case; Br(g)+ 1e^- → Br^-(g), the electron affinity for the non-metals is negative. hence the answer
Yes, that is all correct!
The atomic number is the same as the number of protons (12).
Magnesium = Mg
Atomic mass is 24. 305.