Answer :
Final answer:
The measurement 100.5L has four significant digits, accounting for all non-zero digits and zeros between them as well as the trailing zero which indicates decimal precision.
Explanation:
The correct answer to the question of how many significant figures are in the measurement 100.5L is four significant figures. According to the rules of significant figures:
All non-zero digits are always significant (1 and 5 in 100.5).
Any zeroes between significant digits are significant (00 in 100.5).
Trailing zeroes in a decimal number are significant (0.5 indicates precision).
As such, the measurement has 1, 0, 0, and 5 as its significant digits, totaling to four. Therefore, the correct option is A. 4 significant digits.
4 significant figures. All figures are significant because the zeros are in between two significant digits