24 000
23.43 rounded to two significant figures is 23.
Two.
Two of them and they are 23
0.0175
0.0342
0.0023
3 of them.
0
4 of them.
Using eight significant figures, there are 6.0221421 X 10^23 carbon atoms present in a mole of 12c.
0.6765
6.0221421 x 10^23