Atoms and the Periodic Table

Front

What happens to electrons when atoms absorb precise amounts of energy (quanta)?

Back

Electrons move to higher energy levels.

Front

What is the maximum number of electrons in the innermost energy level of an atom?

Back

2

Front

Which isotope of lead is likely to be the most abundant if the average atomic mass is 207.2?

Back

Lead-207.

Front

What are the columns on the periodic table called?

Back

Groups or families.

Front

Who developed the planetary model of the atom?

Back

Niels Bohr.

Front

What is an atom?

Back

The basic unit of a chemical element, consisting of a nucleus surrounded by electrons.

Front

What is the periodic table?

Back

A tabular arrangement of chemical elements, organized by their atomic number, electron configuration, and recurring chemical properties.

Front

What is an isotope?

Back

Atoms of the same element that have the same number of protons but different numbers of neutrons.

Front

What is atomic mass?

Back

The weighted average mass of an element's isotopes, measured in atomic mass units (amu).

Front

What are valence electrons?

Back

Electrons in the outermost shell of an atom that are involved in chemical bonding.