Answer:
When insulating materials rub against each other, they may become electrically charged . Electrons , which are negatively charged, may be 'rubbed off' one material and on to the other. The material that gains electrons becomes negatively charged
Explanation:
thank me later
Answer:
B
Explanation:
Look on the x-axis for the tick marked "60". This indicates 60 degrees Celsius, which we want. Now, look on the y-axis for the tick marked "60". This indicates 60 grams of 
. Trace along the graph to find where these two places meet at (60, 60).
Now, look for the solubility curve of ; it's the yellow-orange line. Find out what the y-coordinate of the point where x = 60 is on the line: it's around (60, 65).
So, since the point (60, 60) is below the line corresponding to this substance, is unsaturated.
The answer is B.
Moles of K = 32.4/39 = 0.83 mole. According to stoichiometry, 2 moles of K produces 1mole of H2. Therefore, 0.83 mole of K produces = 0.83/2 = 0.415 moles of H2. Therefore number molecules of H2 = moles of H2 x 6.02 x 10^23 = 2.4983 x 10^23 molecules. Hope this helps!
<span>1.15x10^24 molecules of hypothetical substance b
Making the assumption that each molecule in hypothetical substance a reacts to produce a single molecule of hypothetical substance b, then the number of molecules of substance b will be the number of moles of substance a multiplied by avogadro's number. So
Moles hypothetical substance a = 29.9 g / 15.7 g/mol = 1.904458599 moles
This means that we should also have 1.904458599 moles of hypothetical substance b. And to get the number of atoms, multiply by 6.0221409x10^23, so:
1.904458599 * 6.0221409x10^23 = 1.146892x10^24 molecules.
Rounding to 3 significant figures gives 1.15x10^24</span>
