Answer:
A) 5
B) 3
C) 3
D) 4
E) 1
F) 2
G) 3
H) 3
Explanation:
The rule of significant figures is kind of confusing however I will try to explain this in the best way I know:
A) 12.202 since the 0 is sandwiched between two other numbers that are not zeros, this one has 5 sig figs
B) 205 again since the 0 is sandwiched between two other numbers that are not zeros, this one has 3 sig figs.
C) 1.05 again with the previous rules, this also has 3 sig figs
D) 0.0001040 This is is where the rule changes. The first sig fig is the 1, because it is not a 0, however all the zeros before it are not significant. The next zero is significant because of the rule stated previously, this number has 4 sig figs.
E) 0.01 Like explained in the previous step, since the zeros before the one do not have a non zero on both sides they are not significant so this number has 1 sig fig
F) 0.010, Again with E, the significant numbers start at 1, however it ends with a zero and because there is a decimal in this number, that zero is also significant so it has 2 sig figs
G) 1230 So the 1, 2 and 3 are significant, this number ends in 0, however since it does NOT have a decimal, this number is not significant. This number has 3 sig figs
H) -40.0. This number kind of combines all the rules. Because of the decimal both of these zeros are considered significant, so this number has 3 sig figs