at least 10..
Sorry. We can't do your homework for you. Please read the forum guidelines.
Who said thats my homework??
It was a question in Yahoo answers..
Check it out; http://answers.yahoo.com/question/i...CHYqQyuVxnr4SWDYFWr2LRdXEaturQHA--&paid=voted
Okay, in that case, we can't do someone else's homework here either until they come and show what they've attempted.
Whatever, . . .
But i think the question is kinda interesting.
Here is my analysis..
1) Man made elements are very costly.
2) They are higher in atomic number and weight.
3) They are radio-active.
4) They are .. ?
Separate names with a comma.