How many significant figures are present in the following?(i) 0.0025 (ii) 208 (iii) 5005 (iv) 126,000 (v) 500.0 (vi) 2.0034

(i) 0.0025 has 2 significant figures. The leading zeros are not counted as significant figures. Only the '2' and '5' are significant.

(ii) 208 has 3 significant figures. All non-zero digits are always significant.

(iii) 5005 has 4 significant figures. All non-zero digits are always significant and zeroes between non-zero digits are also significant.

(iv) 126,000 has 3 significant figures. In this case, the trailing zeros are not significant because they are simply acting as placeholders.

(v) 500.0 has 4 significant figures. The trailing zero after the decimal point is significant because it indicates a measure of precision.

(vi) 2.0034 has 5 significant figures. All non-zero digits are always significant and zeroes between non-zero digits are also significant.