in the receive tab where all your addresses are, you can right click and from the menu you can choose private key, QR code and other stuff
I do not see an option to find my PUBLIC KEY under the Receive Tab.
I only see the option to get my PRIVATE KEY.
Which version of electrum are you running at the moment ?
I am running Electrum V 1.9.8
If you are using windows, download the new electrum version (beta 2.0b2.exe ) at : https://electrum.org/beta . After import your addresses with your seed, in the new version you can know easily the public key of a bitcoin address:
