Summary Significant Figures: High School Chemistry Notes

Significant Figures​
Chemistry
Introduction: Important Vocab

●​ Measurements: A quantity that has a number and a unit
●​ Accuracy: How close a measurement is to a target
●​ Precision: How consistent the measurements are.



Significant Figures: (Sig figs) in a measurement include all digits that are known

-​ Measurement cannot be more precise than your LEAST precise measurement
-​ Can not use two types of rulers (must make sure method of measurement is the same)



6 Rules for Significant Figures:

●​ Non-zero numbers ARE significant (No zeros in the number)
○​ “123” has 3 sig figs
●​ Sandwiched zeros ARE significant
○​ “101” has 3 sig figs; “1000001” has 7 sig figs
●​ Leading Zeros ARE NOT Significant
○​ “0.01” has one sig fig
●​ Trailing Zeros WITH decimals ARE Significant
○​ “1.0” has 2 sig figs; “5.5000” has 5 sig figs
●​ Trailing Zeros W/O Decimals ARE NOT significant
○​ “1000” has 1 sig fig; “54320” has 4 sig figs
●​ When using scientific notation, ignore the “Times 10 to the 3rd”
○​ “3.201 x 10^9” has 4 Sig Figs