Ch. 7a Review

Front

Who developed a simplified model of the atom?

Back

Niels Bohr

Front

The number of protons plus neutrons is the atom's approximate atomic ______.

Back

mass

Front

A row on the periodic table is called a ____.

Back

period

Front

What is a substance that contains only one kind of atom?

Back

element

Front

Dmitri Mendeleev developed the periodic table of the elements, which ____ elements.

Back

classifies

Front

What is the center of an atom called?

Back

nucleus

Front

What are negatively charged particles in an atom?

Back

electrons

Front

What is the term for the vertical columns in the periodic table?

Back

groups

Front

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

Back

atom

Front

What is the term for the number of protons in the nucleus of an atom?

Back

atomic number