Young copper beads do have yellow or green tail tips and usually a lighter color, but it can vary. It's easy to tell if it's venemous or not by the head. A triangle head is venemous, an oval one is not. These also have pits in the head. Some non venemous will try to look venemous by flailing their necks. My guess is not a copperhead but you need the head to be sure, it has a spot on the top that differentiates it from the look alikes.
If the head is in the gravel be careful, if someone steps on it and it's venemous its still dangerous. I am careful to not bother non venemous snakes, many eat other snakes, bugs or rodents. There are a few that are fantastic at eating other snakes (king snakes) that are great to have around.