So, you scanned the address and imported it to your phone... it just created a watch-only wallet.
You can't use that watch-only Mobile Electrum to spend those coins.
It's basically the same with seeing it on a blockexplorer, except you can make a transaction with it but you can't sign and broadcast it, make sure to keep your PC version and SEED written and stored somewhere safe.

If you wish to use the mobile version alone, you have to import the SEED from the PC wallet to your mobile using the "I already have a SEED" option in the create wallet menu. (You can make 2 or more wallet files in Electrum)