To know how many significant figures are there in the following numbers, we must know the 5 rules of significant figures:
-All non-zero numbers are significant
-Zeros between two non-zero are significant
-Leading zeros are NOT significant
-Trailing zeros to the right of the decimal are significant
-Trailing zeros in a whole number with the decimal show are significant
Then,
i) 0.238 g= 3 significant figures
j) 80.033 dL= 5 significant figures
k) 3.05x10^-2 Mm= 3 significant figures
l) 0.055870 kg= 5 significant figures