Elements
These are pure substances from which all other things are built
Periodic Table
The arrangement of 118 elements
Period
Each horizontal row in the periodic table
Group
Each vertical column on the periodic table
Representative Elements
These have group numbers 1A to 8A
Transition Elements
These are block elements in the center of a periodic table that have group numbers followed by the letter ‘B
Group 1A
These are alkali metals except for Hydrogen
Group 2A
These are alkaline earth metals; these are shiny metals but not as reactive
Group 7A
These are halogens; highly reactive and form compounds with most of the elements
Group 8A
These are noble gases; they are quite unreactive and are seldom found in combination with other elements
lanthanides and actinides
The two rows of 14 elements called the ______, which are part of Periods 6 and 7, are placed at the bottom of the periodic table to allow them to fit on a page.
Metals
These are shiny solids, such as copper, gold, and silver
Nonmetals
They are often poor conductors of heat and electricity
Metalloids
These are elements that exhibit some properties that are typical of metals and other properties that are characteristic of nonmetals
Atom
The smallest unit particle of an element that retains the characteristics of that element
Subatomic Particles
These are even smaller bits of matter
Cathode Rays
These are streams of small particles produced when electricity is applied to a glass tube
Protons
These are the atoms positively charged particles
Electrons
These are the atoms negatively charged particles
Neutrons
These are the atoms neutral particles
Nucleus
The center of the atom
Atomic Mass Unit
A very small unit of mass
Dalton
The atomic mass unit
Atomic Number
This is equal to the number of protons in every atom of that element
Mass Numer
The total number of protons and neutrons in its nucleus
Number of neutrons in a nucleus = mass number
number of protons
Isotopes
These are atoms of the same element that have the same atomic number but different numbers of neutrons
weighted average
Because each isotope has a different mass, chemists have calculated an atomic mass for an “average atom,” which is a ______ of the masses of all the naturally occurring isotopes of that element.
Atomic Symbol
It indicates the mass number in the upper left corner and the atomic number in the lower left corner
Electromagnetic spectrum
It shows the arrangement of different types of electromagnetic radiation in order of increasing energy
atomic spectrum
When light from a heated element passes through a prism, it separates into distinct lines of color separated by dark areas called an _____.
principal quantum numbers
In an atom, each electron has a specific energy known as its energy level, which is assigned values called _____.
electron arrangement
The ______ of an atom gives the number of electrons in each energy level.
Period Properties
These consists of the valence electrons in atoms, the trends in atomic size, ionization energy, and metallic character
Valence Electrons
These are the electrons in the outermost energy level
Electron-Dot Symbol
Also known as a Lewis Structure, represents the valence electrons as dots that are placed on the sides, top, or bottom of the symbol for the element
Ionization Energy
A quantity of energy that is required to remove one of the outermost electrons
Cation
A positive particle
Anion
A negative particle.
Metallic Character
An element that loses valence electrons easily
According to Dalton’s Atomic Theory,
atoms
According to Dalton’s Atomic Theory, All matter is made up of tiny particles called ______.
similar to one another and different from atoms of other elements
According to Dalton’s Atomic Theory, All atoms of a given element are ______________.
compounds
According to Dalton’s Atomic Theory, Atoms of two or more different elements combine to form _______.
chemical reaction
According to Dalton’s Atomic Theory, Atoms are never created or destroyed during a ________.