MathBench > Measurement

Logs and pH

Important Things to Remember about Logs
(or else...)

Logs make it easier to compare measurements that vary by many orders of magnitude.

Positive logs mean big numbers — bigger than one.
To find the approximate log, simply count the number of digits AFTER the first digit.

Negative logs mean small numbers — between zero and one.
To find the approximate log, count the decimal point plus number of zero's UNTIL the first non-zero digit.

log Logs are the same as the exponent you would need to put on a "10" in order to get your original measurement: in other words, The Log is the Power.

Going UP BY ONE on a log scale is always the same as multiplying by 10. Going DOWN BY ONE on a log scale is always the same as dividing by 10.

You can recover the original measurement by raising 10 to the log ( or "10^___ =" on Google).

The pH scale is based on the NEGATIVE log of concentration of H+ ions.

The Richter scale is based on the log of energy released.

 

 

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