Hi! I wanted to ask a question about this problem:

What is the weight of 5.07 × 1021 atoms of
phosphorus?
Answer in units of g.

I got .261 g but I just wanted to know what is the rule to rounding when you are doing this kinds of problems. I am taking my hw online and I don't know how I should round the answers, could you help me?

http://forums.d2jsp.org/forum.php?f=257

Try here.

Hi, as posted in your last thread Homework questions should be asked here:

http://forums.d2jsp.org/forum.php?f=257

Try posting in this subforum:
http://forums.d2jsp.org/forum.php?f=257

You may want to use this part of the forum:

http://forums.d2jsp.org/forum.php?f=257