Test #3 Review Atomic Structure and the Periodic Table

A comprehensive set of flashcards covering key concepts in atomic structure and the periodic table for exam preparation.

What is the definition of Atomic Number?

The number of protons in the nucleus of an atom.

What is the definition of Atomic Weight?

The average mass of an atom of an element, typically measured in atomic mass units (amu).

What subatomic particles make up an atom?

Protons, neutrons, and electrons.

What is a Valence Electron?

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

What are Noble gases?

Elements in Group 18 of the periodic table that are inert and unlikely to react.

How do atoms achieve electrical neutrality?

By having an equal number of protons (positive charge) and electrons (negative charge).

What is the significance of Mendeleev's work on the Periodic Table?

He organized elements by increasing atomic weight and identified periodic trends, leaving gaps for undiscovered elements.

What do Groups represent in the Periodic Table?

Vertical columns that group elements with similar chemical properties.

What do Periods represent in the Periodic Table?

Horizontal rows that indicate the number of energy levels in the atoms of elements.

What is an Isotope?

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

What describes the Bohr Model of the atom?

It illustrates electrons orbiting the nucleus at set energy levels.

What are the characteristics of Metals?

Metals are malleable, ductile, conductive, and typically have a luster.

What is the maximum number of electrons that can fit in the first three energy shells?

1st: 2, 2nd: 8, 3rd: 18.

Why do two strips of plastic repel each other?

Because they have built up like charges after being rubbed together.

What are Metalloids?

Elements that have properties of both metals and nonmetals.

How do atoms hold together?

Through the electromagnetic force between protons and electrons.

What is the definition of a Molecule?

A group of atoms bonded together.

What is the definition of a Particle?

A small localized object to which can be ascribed physical or chemical properties.

What distinguishes a synthetic element?

An element that is not naturally occurring and is created in a laboratory.

What was Dalton's contribution to atomic theory?

He proposed that matter is made up of indivisible atoms and introduced the concept of atomic weights.

What is an Atom?

The smallest unit of matter that retains the properties of an element.