Solutions for your questions are the following:
1. remaining amount is equal to:960 g : 100% = 30 g : xx = 30 g * 100% / 960 g
= 3.125%
= 0.03125
Now, we use this formula to calculate the number of half-lives:(1/2)ⁿ = x,
so,(1/2)ⁿ = 0.03125
to calculate n, use this equation:
n*log(1/2) = log(0.03125) n = log(0.03125)/log(1/2)
= log(0.03125)/log(0.5)
= -1.505/-0.301
n=5
Ifn = 5T = 15 min
Then
L = T/nL = 15 min/5
= 3 minutes
2. You should pick filtration. It is use to separate heterogeneous mixtures just like in the problem stated.
Answer:
Maybe I know too much chemistry but how the metals (and the non-metals) react depends on where they are in the Periodic Table. The metals in groups I and II over on the far left side are explosively reactive and loose electrons and form ionic bonds. Examples: Na+1 has lost 1 electron and Li+2 has lost 2 electrons. The metals in the higher groups are more confusing but most of them share outer shell electrons and form covalent bonds. Examples: Fe2O3 (rust) where Iron shares 2X3 electrons with Oxygen which shares 3X2 electrons. Confused enough? :-)
The answer you'll be expected to give depends on the subject of the chapter you're studying. If you're studying covalent bonds, then the answer will probably be "form covalent bonds". If you're studying ionic bonds, then the answer will be "lose electrons".
Explanation:
This may not be the answer... I'm sorry if it's not
<span>No, the only places that free electrons can exist is in plasma, electrons unbind from their original atoms and bounce around. In the core of the sun, where nuclear fusion occurs, all electrons are unbound from their atoms.</span>