In baseball, a base is "safe" in that a player can not be tagged out if they are on the base before either they, or the base in some instances, are tagged.
safe
safe
Safe.
The base runner is safe at third while the batter is safe at first
true
No ! Not at all !
Home base
No. Contact with a strong base can cause severe chemical burns.
No, as long as he is on the base he is safe
Yes, the runner would be safe.
Actually they are both safe... for now, but play is still live. The lead runner is safe. The trailing runner has to go back to his previous base before being tagged out or running out of the baseline. Or, the lead runner has to advance to the next base before being tagged out, leaving the trailing runner safe at the double-occupied base.