Classify each substance as a pure substance or a mixture.

Solution 37E: All digits of a measurement including uncertain number are called significant figures. Significant figures = all certain digits + one uncertain digit The rules for determining the significant figures are (i) Zeros between nonzero digits are always significant (ii) Zeros at the beginning of a number are never significant. (iiI) Zeros at the end of a number are significant if the number has a decimal point (a) 601 kg, There are three significant figures. This is because , zero is between the non zero digits. So