how many significant figures are in these numbers?

Question

0.1110


1.0


2.00

500,000,000

Answer 1

Significant figures is a way of talking about how precise a number is. The idea being that 1.00 is a more precise number than 1.0 but less than 1.000 since we're talking about measurements which might have a certain level of error inherent in them.

To find the number of significant figures, you start from the leftmost non-zero digit and count to the right until you're done.

So, for example, if you're looking at 0.0023500, you'll start at the 2 and count the digits until you're done (and you should get 5 as your answer). That should give you the quick and easy answer to your first few questions without anyone actually telling you the answer directly (and since this is obviously a homework question, nobody should give you the answer: The purpose of homework is understanding how to do the problem. Coming up with the answer is just a biproduct of that).

Now if there's no decimal point, it gets a bit more difficult to tell exactly how precise a number is supposed to be. In that case, what we do is we start at the left and count until we have nothing but zeros to the right. So, 230 has 2 significant figures (2 and 3), 200 has 1 but note that 200. (see the decimal point?) has three. When this can matter, the usual thing to do is to write all numbers in scientific notation so there's no longer any possibility for ambiguity about whether 200 is meant to have 1 significant figure, 2 or 3.

Answer 2

0.1110
Any numbers to the right of the decimal spot after a number greater than zero are counted as significant. So, this would have 4 (1110)

1.0
This would have 2 because the zero comes after the decimal spot and after a non-zero number.

2.00
This would have 3 same reason as above.

500,000,000
Would have 1 (only the 5). The zeros beyond the 5 are not considered significant because they are before the decimal spot and we do not know whether they were rounded or not.

Answer 3

5

2

3

Answer 4

500,000,000 since there is no decimal, 1.

0.1110
4

1.0
2

2.00
3

Answer 5

4,2 &3 respectively.0 is a s.f only when it comes after a s.f.

Answer 6

4,2,3,1
all non-zeros are sig
zeros btw sig figs are sig
zeros after sig figs bfr a deci point are not sig
zeros after a deci point are sig

Answer 7

http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch1/sigfigs.html

Answer 8

all i see is an uneven scale