Chemistry - Significant Figure Rules Prep

• There is ____ in all measurements.

• uncertainty

Remember, the “certain” digits include

• all numbers read directly off of the measuring device PLUS one extra estimated digit.

The amount of definite digits depends on the

measuring device.

An exact number has no uncertainty, and therefore

• has an infinite number of significant figures

Defined quantities are considered to be

exact

All non-zero digits are

significant

Leading zeros are ___ significant

never

Captive zeros are

always significant

Trailing zeros are

sometimes significant

Trailing zeros are sometimes significant (zeros at the end)

They are significant if the number contains a

decimal point

Trailing zeros are sometimes significant (zeros at the end)

b) They are not sig. if the number does not contain a

decimal point