The closeness of a measurement to its true value is a measure of its accuracy. This term is the degree of which a certain measurement conforms to the correct value or the standard value. It is not the same with the term precision. Precision, on the other hand, is a measure used to characterize the closeness of the data measured.
<u>Answer:</u> The magnitude rating for an earthquake causing an amplitude 10,000,000 times
is 7.
<u>Explanation:</u>
Richter scale is defined as the scale which expresses the magnitude of earthquake on the basis of the seismograph oscillations.
The equation used to measure the magnitude of an earthquake on Richter scale is:

where
I = amplitude registered on seismograph 100 km away from seismic center = 
= small amplitude
Putting values in above equation, we get:

Hence, the magnitude rating for an earthquake causing an amplitude 10,000,000 times
is 7.
Answer:
tha mass of magnesium nitrate is 592g
Explanation:
from a balanced chemical equation
2HNO3 + Mg(OH)2→ Mg(NO3)2 + 2H2O
2 mol of nitric acid is equivalent to 1 mol of magnesium nitrate. then 8 mol of nitric acid will be equivalent to 4 mol of magnesium nitrate.
Answer: - 436.5 kJ.
Explanation:
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation.
The given chemical reaction is,

Now we have to determine the value of
for the following reaction i.e,

According to the Hess’s law, if we divide the reaction by half then the
will also get halved and on reversing the reaction , the sign of enthlapy changes.
So, the value
for the reaction will be:


Hence, the value of
for the reaction is -436.5 kJ.