Which Fundamental Force is Involved?

[funkmetalbass]

Homework Statement

Which of the four fundamental interactions is most likely responsible for the following reactions?
(a) $${}^{16}O\text{ (excited state) }\longrightarrow{}^{16}O\text{ (ground state) }+\gamma$$
(b) $${v}_{e}+e\longrightarrow v_{e}+e$$
(c) $$p+\overline{p} \longrightarrow \gamma + \gamma$$
(d) $$p+\overline{v}_e \longrightarrow n + e^{+}$$
(e) $${\pi}^{0} + p \longrightarrow {\pi}^0 + p$$
(f) $${}^{3}H \longrightarrow {}^3He + e^{-} + \overline{v}_{e}$$

Homework Equations

None that I can see.

The Attempt at a Solution

(a) Electromagnetic interaction - photon presence
(b) Weak interaction - leptons don't participate in strong interaction
(c) Electromagnetic interaction - photon presence
(d) ?
(e) ?
(f) Weak interaction - leptons don't participate in strong interaction

The book doesn't give any hints or real means of determining which forces are involved, and the laws of conservation aren't discussed until the next section. What should I be looking for to figure out which interaction involved?

 

[vela]

For (b) and (e), the reason you state only shows it's not a strong interaction. You should give a more convincing reason they are weak interactions and not electromagnetic.

Hint: Just like the photon implies electromagnetism, what particles always imply the weak interaction?