12/15 -Unit Review: Atoms

A(n) is the smallest piece of an element that still represents that element.

In the nucleus are , which are atomic particles with a positive charge.

James Chadwick discovered the , a particle in the nucleus with neutral/zero charge.

The atomic model by Neils Bohr proposed that move in circular orbits, or energy levels around the nucleus.

In the modern atomic model, electrons form a(n) which is an area around the nucleus in which an electron is likely to be located.

The atomic number is the number of in one atom of an element.

The mass number is the total number of and in one atom of an element.

In a neutral atom, the number of must equal the number of .

-- are atoms of the same element that have different numbers of neutrons.

Around 1868, Russian chemist created the to help classify the known elements by their physical and chemical properties.

In the periodic table, a column is called a and a row is called a .

Elements in the same have similar chemical properties.

Most elements in the PT are , which have a shiny luster and are good conductors.

-- are on the right side of the PT; which have properties opposite of metals.-

Between the metals and nonmetals are the , which have properties of both.