Atomic Mass and Units of Measurement

Flashcards about atomic mass and units of measurement in chemistry.

What is Chemistry?

The field of science developed to understand what is happening at an almost unimaginably small scale, particularly the atomic and subatomic scale.

What is an atomic mass unit (amu)?

A unit historically used by the chemistry community to measure mass at a small scale.

What is a unified atomic mass unit?

A more modern version of the atomic mass unit, denoted by 'u'.

What is the mass of one unified atomic mass unit in kilograms?

Defined as 1.66054 x 10^-27 kilograms.

What is the approximate mass of a proton?

Approximately one unified atomic mass unit.

What is the approximate mass of a neutron?

Approximately one unified atomic mass unit.

What primarily determines the mass of an atom?

Determined mainly by the number of protons and neutrons in the nucleus.

What is the atomic number?

The number on top of an element's abbreviation on the periodic table, indicating the number of protons.

What are isotopes?

Versions of a given element with the same number of protons but different numbers of neutrons.

What is the approximate mass of the most common form of hydrogen?

The mass of a proton plus an electron, approximately one unified atomic mass unit.

What is average atomic mass?

A weighted average of the masses of various isotopes of an element.

What is atomic weight?

The term used in older chemistry books for average atomic mass.

What is relative atomic mass?

These numbers are unitless and represent the mass of an element relative to the mass of a hydrogen atom.