Chemistry Quiz

What are significant figures

Significant figures are the digits in a measurement that show its precision.

How do you determine the number of significant figures in a reported value

Count all certain digits plus one estimated digit, following the rules for zeros.

How do you perform mathematical calculations with significant figures

For multiplication and division, the answer has the same number of significant figures as the measurement with the fewest significant figures. For addition and subtraction, the answer has the same number of decimal places as the measurement with the fewest decimal places.

What is scientific notation

Scientific notation expresses a number as a value between 1 and 10 multiplied by a power of 10.

How do you convert a number to scientific notation

Move the decimal until only one nonzero digit is to the left of it, then use the number of places moved as the exponent of 10.

How do you convert scientific notation back to standard notation

Move the decimal the number of places indicated by the exponent. A positive exponent moves it right, and a negative exponent moves it left.

What is precision

Precision is how closely repeated measurements agree with each other.

What is accuracy

Accuracy is how close a measurement is to the accepted or true value.

What is the difference between precision and accuracy

Precision describes how close measurements are to each other, while accuracy describes how close a measurement is to the accepted value.

How do you calculate error

Error is the difference between the experimental value and the accepted value: experimental value − accepted value.

How do you calculate percentage error

Percentage error is |experimental value − accepted value| ÷ accepted value × 100%.

How do you change a number to scientific notation

Move the decimal so there is one nonzero digit before it and use the number of places moved as the exponent.

How do you change a number from scientific notation to standard notation

Move the decimal based on the exponent: right for positive and left for negative.

What is a basic measurement

A basic measurement is a measurement made directly using an instrument, such as measuring mass, length, time, temperature, or volume.

What is a derived measurement

A derived measurement is calculated from basic measurements, such as density, which is mass divided by volume.

What is the metric Stairway used for

The metric Stairway is used to convert between metric units by moving the decimal.

How do you use the metric Stairway

Moving to the right means moving the decimal to the right; moving to the left means moving the decimal to the left. Each step represents a factor of 10.

What happens when you move down the metric Stairway toward smaller units

Move the decimal to the right.

What happens when you move up the metric Stairway toward larger units

Move the decimal to the left.

What are the common metric prefixes on the metric Stairway

Kilo, hecto, deka, base unit, deci, centi, and milli.

What are the common temperature scales used in chemistry

Celsius, Kelvin, and Fahrenheit.

What is the formula for converting Celsius to Kelvin

K = °C + 273.15.

What is the formula for converting Kelvin to Celsius

°C = K − 273.15.

What is the formula for converting Celsius to Fahrenheit

°F = (°C × 9/5) + 32.

What is the formula for converting Fahrenheit to Celsius

°C = (°F − 32) × 5/9.

What are the five basic values that chemists commonly measure

Mass, length, volume, temperature, and time.

What is the common unit for mass

Grams (g).

What is the common unit for length

Meters (m).

What is the common unit for volume

Liters (L).

What is the common unit for temperature

Degrees Celsius (°C) or Kelvin (K), depending on the measurement.

What is the common unit for time

Seconds (s).

What should you remember about significant figures when reporting a calculated answer

Do not report more precision than is supported by the measurements used in the calculation.

What is the difference between a basic measurement and a derived measurement

A basic measurement is measured directly, while a derived measurement is calculated using one or more measurements