Question

the distance between the two hydrogen atoms in a molecule of water is 0.000000000172 m. express this distance in scientific notation. ○ 1.72 × 10⁻¹⁰ m ○ 1.72 × 10¹⁰ m ○ 0.172 × 10⁻¹⁰ m ○ 17.2 × 10⁹ m ○ 1.72 ×10⁻⁹ m

Explanation:

Step1: Recall scientific notation rules

Scientific notation is in the form \( a \times 10^n \), where \( 1 \leq |a| < 10 \) and \( n \) is an integer. For a number less than 1, we move the decimal point to the right until we get a number between 1 and 10, and \( n \) is negative (equal to the number of places we moved the decimal).

Step2: Process the given number

The number is \( 0.000000000172 \). Move the decimal point 10 places to the right to get \( 1.72 \). So \( n=-10 \).

Step3: Write in scientific notation

So the number in scientific notation is \( 1.72 \times 10^{-10} \) m.

Answer:

A. \( 1.72 \times 10^{-10} \) m