Answer
Normal numbers:
10.78: 4 significant figures;
6.78: 3 significant figures;
0.78: 2 significant figures;
If they were pH values:
10.78: 2 significant figures
6.78: 2 significant figures
0.78: 2 significant figures
The difference is, for pH, we only count the significant numbers after the decimal point.
Work Step by Step
Normal numbers:
10.78: 4 significant figures;
6.78: 3 significant figures;
0.78: 2 significant figures;
If they were pH values:
10.78: 2 significant figures
6.78: 2 significant figures
0.78: 2 significant figures
The difference is, for pH, we only count the significant numbers after the decimal point.
This is true for any logarithm representation.
