11) The measurement 0.000 0043 m, expressed correctly using scientific notation, is
A) 4.3 x 10-7 m.
B) 4.3 x 10-6 m.
C) 4.3 x 106 m.
D) 0.43 x 10-5 m.
E) 4.3 m.
12) The number 680 000 000 expressed correctly using scientific notation is
A) 6.8.
B) 0.68 x 106.
C) 6.8 x 108.
D) 68 x 107.
E) 680 x 106.
13) Which of the following numbers is the smallest?
A) 4.0 x 10-6
B) 4.0 x 10-8
C) 4.0 x 10-2
D) 4.0 x 1015
E) 4.0 x 10-12
14) Which of the following has the smallest mass?
A) 4.0 x 10-6 g
B) 4.0 x 109 ng
C) 4.0 x 10-2 μg
D) 4.0 x 10-3 kg
E) 4.0 x 10-6 mm
15) Which of the following numbers is the largest?
A) 2.05 x 103
B) 2.05 x 10-12
C) 2.05 x 105
D) 2.05 x 108
E) 2.05
16) Which of the following conversion factors is a measured number?
A) 10 cm/dm
B) 12 in/ft
C) 16 oz/lb
D) 25 miles/gallon
E) 12 eggs/dozen
17) Significant figures are important because they indicate
A) the accuracy of a measurement.
B) the number of digits on a calculator.
C) the number of measurements.
D) the precision of a measurement.
E) the accuracy of the conversion factor.
18) Which of the following measurements has three significant figures?
A) 0.005 m
B) 510 m
C) 0.510 m
D) 0.051 m
E) 5100 m
19) Which of the following numbers contains the designated CORRECT number of significant figures?
A) 0.043005 significant figures
B) 0.003022 significant figures
C) 156 0003 significant figures
D) 1.042 significant figures
E) 3.06504 significant figures
20) The number of significant figures in the measurement of 45.030 mm is
A) none.
B) three.
C) four.
D) five.
E) six.
The Correct Answer and Explanation is :
Let’s go through each question with the correct answers and explanations.
11) The measurement 0.000 0043 m, expressed correctly using scientific notation is:
Answer: B) 4.3 x 10⁻⁶ m
Explanation: In scientific notation, we express the number as a product of a number between 1 and 10 and a power of 10. To convert 0.0000043 to scientific notation, move the decimal point 6 places to the right, which gives us 4.3. Therefore, it becomes 4.3 x 10⁻⁶ m.
12) The number 680 000 000 expressed correctly using scientific notation is:
Answer: C) 6.8 x 10⁸
Explanation: 680,000,000 can be written as 6.8 when we move the decimal point 8 places to the left, which makes it 6.8 x 10⁸.
13) Which of the following numbers is the smallest?
Answer: B) 4.0 x 10⁻⁸
Explanation: The smaller the exponent of 10, the smaller the number. Here, 4.0 x 10⁻⁸ is the smallest number because the exponent is negative, which means the value is less than 1.
14) Which of the following has the smallest mass?
Answer: A) 4.0 x 10⁻⁶ g
Explanation: We compare the values of the numbers by converting them to a consistent unit or considering the size of the exponent. 4.0 x 10⁻⁶ g is the smallest mass compared to the other options.
15) Which of the following numbers is the largest?
Answer: D) 2.05 x 10⁸
Explanation: The number with the largest exponent of 10 will be the largest number. In this case, 2.05 x 10⁸ has the largest exponent.
16) Which of the following conversion factors is a measured number?
Answer: D) 25 miles/gallon
Explanation: A conversion factor like “25 miles/gallon” involves a real-world measurement of fuel efficiency, as opposed to exact numerical relationships like “10 cm/dm” (which is defined exactly) or “12 eggs/dozen.”
17) Significant figures are important because they indicate:
Answer: A) the accuracy of a measurement.
Explanation: Significant figures reflect the precision of the measurement process and the accuracy of the measuring tool used.
18) Which of the following measurements has three significant figures?
Answer: B) 510 m
Explanation: The number 510 m has three significant figures because both the 5 and the 1 are significant, and the 0 is significant because it is between non-zero digits.
19) Which of the following numbers contains the designated CORRECT number of significant figures?
Answer: E) 3.06504 significant figures
Explanation: 3.06504 has six significant figures, as all digits are significant, including the zero between the 6 and 5.
20) The number of significant figures in the measurement of 45.030 mm is:
Answer: D) five.
Explanation: The number 45.030 has five significant figures because the leading 4 and 5 are significant, and the zeros after the decimal point are also significant.
These answers reflect the key rules in scientific notation, significant figures, and conversions, which are essential in presenting accurate and precise data.