Chemistry Midterm Review

Front

What is significant figures?

Back

Significant figures are the digits in a number that contribute to its precision. This includes all non-zero digits, any zeros between significant digits, and trailing zeros in the decimal portion.

Front

How many significant figures are in the number 0.007 m?

Back

Two significant figures.

Front

What is the atomic number of potassium (K)?

Back

The atomic number of potassium (K) is 19, which indicates it has 19 electrons.

Front

What particles are found in the nucleus of an atom?

Back

The nucleus of an atom contains protons and neutrons.

Front

What is a pure substance?

Back

A pure substance is a material that has a constant composition and consistent properties throughout. Examples include elements and compounds.

Front

Which of the following is a pure substance: egg, gold, sea water, or bronze?

Back

Gold is a pure substance.

Front

What is the mass of an electron in atomic mass units (amu)?

Back

The mass of an electron is considered to be 0 amu.

Front

What is the difference between an element and a compound?

Back

An element is a pure substance that cannot be broken down into simpler substances, while a compound is a substance formed when two or more elements chemically bond together.

Front

What is the formula for calculating the number of protons in an atom?

Back

The number of protons in an atom is equal to its atomic number.

Front

What is the charge of a proton?

Back

A proton has a positive charge.