Atomic Structure & History

Front

Particles in an atom that are neutral and have no charge are

Back

Neutrons

Front

An element has isotopes with the following mass numbers and abundances: 241: 81%, 242: 12%, 243: 7%. What is the best estimate of its average atomic mass?

Back

241.2

Front

Who used the word 'atomos' to describe the uncuttable (indivisible) atom?

Back

Democritus

Front

If an atom contains exactly six protons, then it's an atom of _____

Back

Carbon

Front

Which part of an atom is used to identify it?

Back

Number of protons

Front

What is the smallest unit of an element that retains the properties of that element?

Back

Atom

Front

What is the charge of a proton?

Back

Positive charge

Front

What is the charge of an electron?

Back

Negative charge

Front

What is the mass of a neutron compared to a proton?

Back

Approximately equal

Front

What is an isotope?

Back

Atoms of the same element with different numbers of neutrons.