Periodic Table Study Guide

What does the atomic number represent in the periodic table?

It is the number by which elements are arranged, representing the number of protons in the nucleus of an atom.

Define 'Group' in the context of the periodic table.

A vertical column in the periodic table that contains elements with similar properties and the same number of valence electrons.

What is a 'Period' in the periodic table?

A horizontal row of elements in the periodic table that corresponds to the number of energy levels in the atoms.

What characterizes metals in the periodic table?

They are primarily on the left side, lose electrons to form cations, have low ionization energy and low electronegativity, and are good conductors of heat and electricity.

Define 'Nonmetals' as found in the periodic table.

Elements located on the right side of the staircase that gain electrons to form anions and have high electronegativity and ionization energy.

What are metalloids?

Elements with properties of both metals and nonmetals, typically located above and below the staircase on the periodic table.

What is ionization energy?

The energy needed to remove an electron from an atom; noble gases have the highest, while metals have the lowest.

What trend occurs as you move down a group in the periodic table?

Atomic radius increases, ionization energy decreases, electronegativity decreases, and metallic character increases.

How does atomic radius change across a period?

It decreases as you move from left to right due to increased nuclear charge attracting electrons more strongly.

What are Alkali Metals?

Group 1 elements that are extremely reactive and have 1 valence electron.

Describe Alkaline Earth Metals.

Group 2 elements that are reactive and have 2 valence electrons.

What defines Transition Metals?

Elements in groups 3-12 that often have multiple oxidation states and can form colored solutions.

What are Chalcogens?

Elements in group 16 with 6 valence electrons, including both nonmetals at the top and metals at the bottom.

Define Halogens.

Group 17 elements that have 7 valence electrons, are diatomic, and are the most reactive nonmetals.

What characterizes Noble Gases?

Group 18 elements that have 8 valence electrons, are stable with a complete octet, and are unreactive.