Chapter 2: Measurements, Units, and Scientific Notation in Chemistry

What is scientific notation used for?

To express numbers in a compact form, especially very large or very small numbers.

What is the value of one mole in scientific notation?

6.022 x 10²³.

How do you determine the sign of the exponent when converting to scientific notation?

Move the decimal point left for a positive exponent and right for a negative exponent.

What is the difference between accuracy and precision in measurements?

Accuracy refers to how close a measurement is to the true value, while precision refers to how repeatable a measurement is.

What does uncertainty in measurements refer to?

The degree to which the last digit of a measurement is uncertain.

What are significant figures?

Digits in a number that contribute to its precision, including all non-zero digits, interior zeros, and trailing zeros in a decimal.

How many significant figures are in the number 379?

Three significant figures.

What is the rule for rounding significant figures in multiplication and division?

The final answer must have the same number of significant figures as the measurement with the least significant figures.

What is the rule for rounding significant figures in addition and subtraction?

The final answer must have the same number of decimal places as the measurement with the least decimal places.

What is the metric unit for length?

Meter (m).

What is the metric unit for mass?

Kilogram (kg).

What is the freezing point of water in Celsius?

0°C.

What is the boiling point of water in Celsius?

100°C.

What is the conversion factor from kilometers to miles?

1 kilometer is approximately 0.621371 miles.

What is the prefix for one million in metric units?

Mega (M), which represents 10⁶.

What is the prefix for one billion in metric units?

Giga (G), which represents 10⁹.

What is the prefix for one trillion in metric units?

Tera (T), which represents 10¹².

How do you convert 37 inches to feet?

Divide by 12, resulting in approximately 3.083 feet.

What is the conversion factor for centimeters to inches?

1 inch is equal to 2.54 centimeters.

What is a derived unit?

A unit that is a combination of two or more base units.

What is the formula for converting miles per hour to meters per second?

Multiply by 0.44704.

What is the significance of trailing zeros in a decimal number?

Trailing zeros are significant when they come after a decimal point.

What is the significance of leading zeros in a decimal number?

Leading zeros are not significant.