Answer:
There was an improvement in accuracy. There was no change in precision.
Explanation:
<em>The average mass after recalibration is closer to the mass of the standard, </em>so the recalibration improved the accuracy<em> </em>(the measurement is closer to an accepted 'true' value).
The standard deviation did not change, so the precision (or how disperse the measurements are) was not affected.
July 9, 1958: in Lituya Bay<span>, Alaska was caused by a landslide triggered by an 8.3 magnitude earthquake.</span>
This is a chemical change because there is a new substance that was created and the new chemical can cause other chemical reaction to happen compared to the 1st state of chemical that was in the cave. Because the cave water was exposed to another environment, the calcium bicarbonate, which is also known as salt. When the cave's groundwater was exposed to a different environment the atom in the cave water rearranged and crystallized.
Answer: There are
molecules in 63.00 g of 
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number
of particles.
To calculate the moles, we use the equation:

1 mole of
contains =
molecules
Thus 3.5 moles of
contains =
molecules.
There are
molecules in 63.00 g of 
Molar mass:
HF = 1 + 19 = 20.0 g/mol
Number of moles :
124 / 20.0 => 6.2 moles
Volume = 2.4 L
M = n / V
M = 6.2 / 2.4
M = 2.6 M
Answer A
hope this helps!