Which number has one significant figure: $4xx10^(-23)$ or $4.0xx10^(-23)$ ?

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Answer 1 · 2015-09-19T19:57:46

It would be $4xx10^(-23)$ . $4.0xx10^(-23)$ would have two sig figs.

Answer 2 · 2015-09-19T19:58:51

the correct answer is $4xx10^(-23)$

$4xx10^(-23)$ is one significant figure.

$4.0xx10^(-23)$ is two significant figures since it contains a trailing zero in a number that has a decimal point.

Here is a full explanation on significant figures:
enter image source here

Source: Screenshot from my teaching notes.

Which number has one significant figure: 4xx10^(-23)4xx10^(-23) or 4.0xx10^(-23)4.0xx10^(-23)?