The chasing and biting are most likely playful habits he has learned as a little puppy. Of course at 10 weeks he's not little any more and those teeth are sharp.
You need to be firm and strong. Establish rules and let your pup know that you are the master. Tell your kids not to run away from him, this only encourages the dog to think he is playing with them, a light smack on the nose is hated by most dogs. Without hurting them, you will show you are displeased.
The most important thing is for everyone to be tolerant and only one person to discipline, other wise the dog will get confused and upset. Always remember to praise your pup even for little things, he will love your praise and want more.
Your dog is very young and may be missing his siblings, give him plenty of love. Take him out into the open and let him run his heart out.
A dog gives you unconditional love, but you have to love it back.