Question

1.3.2 test (cst): science and engineering
question 9 of 25
the diameter of a human blood cell is 0.0000062 m. how can this number best be expressed in scientific notation?
a. 6.2 × -10⁶ m
b. 6.2 × 10⁻⁶ m
c. 62 × 10⁻⁵ m
d. 6.2 × 10⁻⁵ 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 the exponent \( n \) is negative (equal to the number of places we moved the decimal).

Step2: Analyze the given number

The number is \( 0.0000062 \). We move the decimal point 6 places to the right to get \( 6.2 \) (since \( 0.0000062 = 6.2 \times 10^{-6} \), because we moved the decimal 6 places right, so the exponent is -6).

Step3: Evaluate the options

• Option A: \( 6.2 \times -10^6 \) is incorrect notation (should be \( 6.2 \times 10^{-6} \), not with a negative sign on 10 like that).
• Option B: \( 6.2 \times 10^{-6} \) matches our calculation.
• Option C: \( 62 \times 10^{-5} \) has \( a = 62 \) which is not between 1 and 10, so incorrect.
• Option D: \( 6.2 \times 10^{-5} \) has the wrong exponent (we moved the decimal 6 places, not 5).

Answer:

B. \( 6.2 \times 10^{-6} \) m