Answer:
Let No be initial no of atoms
N = N0 / 2 after 1 half-life
N = N0 / 4 after 2 half-lives
So after 2 half-lives 20 of the 80 atoms remain
A, hope this helped! I didn’t really get it but I think it’s correct?
the different kids of food and the amount you should eat of them.
green:veggies
red:fruits
orange:grains
purple:protein
blue:dairy
Astronomers can measure a star's position once, and then again 6 months later and calculate the apparent change in position. The star's apparent motion is called stellar parallax. The distance d is measured in parsecs and the parallax angle p is measured in arcseconds.
I hope this helps!
We don't have enough information in the picture to answer that question.
The disembodied right hand could just as well grab the wire in the other direction, with the thumb pointing to the right.
Maybe if we knew WHY the hand is holding the wire in this direction, and what other electrical phenomenon may be involved, we might be able to say something about the current in the wire.
(Actually, we don't even know if it's a wire. It might be a soda straw, a coat hanger, or a pool cue.)