Study Guide: Atomic Theory and the Periodic Table

Democritus

First atomic theorist.

Atomos

Means 'uncuttable'.

Billiard Ball or Pool Ball Model

John Dalton's model of the atom.

Dalton's belief

All matter is made up of tiny, indivisible particles called atoms.

Plum Pudding or Blueberry Muffin Model

JJ Thomson's model of the atom.

Electron

Discovered by JJ Thomson.

Thomson's model description

Negative electrons are embedded in a sphere of positively charged particles.

The Cloud Model

Ernest Rutherford's model of the atom.

Proton and Nucleus

Discovered by Ernest Rutherford.

Rutherford's theory

Atoms are mostly empty space with a small dense positively charged nucleus.

Neutron

Discovered by James Chadwick.

Bohr's expansion

Electrons travel in orbits or shells.

Electron Cloud Model

Current model of the atom with a nucleus surrounded by randomly appearing/disappearing electrons.

Element

A substance that consists of only one kind of atom.

Atom

Smallest particle that an element may be divided into and still be the same substance.

Charge and location of the proton

Positive (+) in the nucleus.

Charge and location of the electron

Negative (-) in shells around nucleus/electron cloud.

Charge and location of the neutron

Neutral (0) in the nucleus.

Atomic Number

Number that tells you the number of protons in each box on the periodic table.

Atomic Mass

Number that tells you the number of protons and neutrons in each box on the periodic table.

Calculating number of neutrons

Atomic mass - Atomic number = number of neutrons.

Horizontal rows on the periodic table

Called periods.

Groups

The vertical columns on the periodic table.

Number of energy levels/shells

What the horizontal rows tell you about the elements in that row.

Number of valence electrons (e-)

What the vertical columns tell you about the elements in that column.

Valence electrons

Number of electrons in the outer shell (determine chemical properties).

Isotope

An atom which has more or less neutrons than it should.

Ion

An atom which has more or less electrons than it should.

Protons

An element is defined by the number of protons it has.

Period

The term that describes the number of 'shells' an atom has.

Group

The term that describes the number of e- on the outer shell of an atom.

Fluorine

Period 2, Group 17.

Calcium

Period 4, Group 2.

Argon

Period 3, Group 18.

Hydrogen

Period 1, Group 1.

Antimony

Period 5, Group 15.

Atom

The largest unit in the list: atom, nucleus, protons, quark.

Nucleus

The second largest unit in the list: atom, nucleus, protons, quark.

Protons

The third largest unit in the list: atom, nucleus, protons, quark.

Quark

The smallest unit in the list: atom, nucleus, protons, quark.

Atomic Number (# of p+)

The number of protons in an atom.

Atomic Symbol

The symbol representing an element.

Name of Element

The name given to a specific element.

Atomic Mass (# of P+ and N0)

The total number of protons and neutrons in an atom.

Increasing atomic number

How the elements are arranged on the periodic table.

Dimitri Mendeleev

The 19th century chemist who created the periodic table.

7

The number of periods on the periodic table.

Energy levels

What the periods on the periodic table tell you about the elements in that row.

Transition Metals

The family of metals that includes Iron (Fe), Cobalt (Co), and Nickel (Ni), which are ferromagnetic.

Alkali metals

The family of metals that is the most reactive and can explode if exposed to water.

Metalloids

Which family has properties of both metals and nonmetals?

Alkali Metals

Which family can explode if exposed to water?

Alkaline Earth Metals

Which two metal families are not found freely in nature?

Noble Gases

Why do noble gases not form compounds readily?

Halogens

Which nonmetal family is as reactive as Alkali Metals?

Halogen

What does the term Halogen mean?

Non-metals

Which family is found in group 1, 14-16, and does not conduct electricity or heat well?

Non-metals

Which family easily forms acids?

Rare Earth Metals

Which family is almost entirely radioactive?

Ion+

What does an atom become when it loses one or more electrons?

Ion-

What does an atom become when it gains one or more electrons?

Isotope

What is an atom that has more or less neutrons than on the periodic table?

Other Metals

Which family when it bonds with other elements creates a light metal or alloy?

Metals vs. Nonmetals

Compare AND Contrast the three differences between metals and nonmetals.

Energy Transmission

Metals: Conductors of heat and electricity. Non-metals: Insulators.

Flexibility

Metals are malleable and ductile, non-metals are brittle.

Luster

Metals have luster (shiny), non-metals are dull.

Fraction/Percentage of Total Elements

Metals 75% (3/4) of periodic table, non-metals 25% (1/4).

Metalloid (Step Line)

What separates metals from nonmetals on the periodic table?

Metalloids

Why are Metalloids called semiconductors? List an example.

Metals

If you were holding the periodic table, where would you look to find the metals?

Nonmetals

Where are all the nonmetals located on the periodic table?

Stable Atom

An atom is stable when its outer shell is full with 2 or 8 electrons.

Noble Gas Family

Why is helium part of the Noble Gas Family?

Ionic Bond

What type of bond forms between a metal and nonmetal?

Covalent Bond

What type of bond forms between two nonmetals?

Polyatomic Bond

What type of bond forms between one metal & at least two different nonmetals?

Ionic Bond Charges

In an ionic bond what are the charges of the metal and nonmetal?