CHEM 001 Lecture Notes - Lecture 2: Trailing Zero, Significant Figures, Decimal Mark

• School: College of The Sequoias
• Department: Chemistry (CHEM)
• Course: CHEM 001
• Professor: guerra

Document Summary

Counting significant figures: non-zeros are always significant, there are three types of zeroes, some are significant, leading zeros are never significant, sandwiched zeros are always significant, trailing zeros are sometimes significant, if there is a decimal point. 1 atm = 760 torr: formula numbers, a unit is never exact if it exist in decimal amounts. The result has the same number of decimal places as the least precise measurement used in the calculation. 19. 6 (1 decimal place) + 58. 33 (2 decimal places) - 4. 974 (3 decimal places) = It"s possible to gain sig-figs by addition and to lose them by subtraction. The result has the same number of significant figures as the least precise measurement used in the calculation. In a series of calculations, don"t round (to adjust the sig-figs) until the end. For different kinds of operations, evaluate the sig-figs in the intermediate answer then do the remaining steps. 3. 489 x 3. 37 (1 dp, 2 sf)