I had the same question for my doctors, and they said it's 'Pr-Pubescence' I was like, 'What?!' She's 7!! But apparently, it is normal... and it's just going to get worse...
The best I've learned to do is not argue back, because when you do, you end up stuck in their childish cycle... like when they start shouting, 'I don't like you! I'm going to run away!' Don't yell 'I don't like you either!' lol it's tempting sometimes to argue back the same way they're treating you but have to remember to just stick to your guns and rather then be childish with them, just remind them what they were asked to do.
The only time I really hear the attitude from my daughter is when I ask her do something and she doesn't want to do it... I sometime hear it when she's trying to do something and she doesn't like what her brother is doing, like maybe she doesn't want him to join her in her little pretend tea party, but he wants to play, or maybe she does want him to play and he doesn't want to play with her at that moment, the attitude comes exploding out like a volcanic eruption lol
So example, I ask her to pick up her toys, she refuses, sometimes even throws the toys I asked her to pick up, I send her to her room to 'Take a break and calm down' She'll shout tons of stuff at me, including that she wants to 'run away' and all I say back is 'You are in there because I asked you to clean up your toys and you refused and even threw them, so you are being punished for your actions and need to take a moment to think about what you did and what you could have done better.'
Of course she still doesn't say anything rash to my comment, but after awhile, she'll calm down and then come down the stairs and say she's sorry for acting the way she did and promise not to do it again and then actually clean up the toys that I asked her to do in the first place
That's the best advice I can give for it, unfortunately there's no 'magic' cure or behavior 'snap' that'll make them stop, all you can do is learn to help control their attitude explosions when they happen