unable to mount a partition.

I'm using RHEL7(version 7.3) on KVM. I've created a partition of disk and now I want to mount it on a directory in root file but I get following error:-

"mount: wrong fs type, bad option. bad superblock on /dev/vda7, missing codepage or helper program, or other error. In some cases useful info is found in syslog -try dmesg | tail or so."

Here vda7 is the partition that I've created. The command for formatting the file system that I've entered is : "#mkfs.ext4 /dev/vda7". As I run "fdisk -l" command, the partition is included in the list.
Please guide me if somewhere I am wrong .