Elements and the Periodic Table

Front

The spontaneous emission of radiation by an unstable atomic nucleus is called __________.

Back

radioactivity

Front

A column of elements in the periodic table is called a group, or __________.

Back

family

Front

Each element is given a specific _______ _______ that usually consists of one or two letters.

Back

chemical symbol

Front

Mendeleev created the first periodic table by arranging elements in order of __________.

Back

increasing atomic mass

Front

At room temperature, more than half of the nonmetals elements are __________.

Back

gases

Front

The horizontal rows in the periodic table are called __________.

Back

periods

Front

Elements in the same group of the periodic table have similar __________.

Back

chemical properties

Front

The atomic number of an element is defined as the number of __________ in its nucleus.

Back

protons

Front

The periodic table is organized based on the __________ of elements.

Back

atomic structure

Front

Metals are typically __________ at room temperature, except for mercury.

Back

solids