midterm review 3

Front

What does accuracy measure in scientific terms?

Back

Accuracy measures how close your answer is to the correct or accepted answer.

Front

What is the charge of a cation?

Back

A cation has a positive charge.

Front

What is the term for atoms of the same element with different mass numbers?

Back

These are called isotopes.

Front

How do you calculate percent error?

Back

Percent error = |(Experimental Value - Theoretical Value)| / Theoretical Value x 100%.

Front

What is the percent error for the density of iron if the experimental value is 7.75 g/mL and the theoretical value is 7.86 g/mL?

Back

The percent error is 1.4%.

Front

How should the answer to the calculation (8.314)(3.160) be recorded in terms of significant figures?

Back

The answer should be recorded as 26.27.

Front

What is a significant figure?

Back

A significant figure is any non-zero digit, any zeros between significant digits, and any trailing zeros in a decimal.

Front

What is the difference between precision and accuracy?

Back

Precision refers to how reproducible measurements are, while accuracy refers to how close a measurement is to the true value.

Front

What is a molecule?

Back

A molecule is a group of two or more atoms bonded together.

Front

What is a compound?

Back

A compound is a substance formed when two or more different elements are chemically bonded together.