Elements and Atoms

Unit Two:

Elements and Atoms

Unit Two:

Elements and Atoms

Table of Contents:
Pg. 1 / Table of Contents
Pg. 2-3 / History
Pg. 4 / About the Periodic Table
Pg. 5-7 / Labels
Pg. 8 / Periodic Table Trends (assignment on pg. 24)
Pg. 9-10 / Lab Two: Trends in the Periodic Table
Pg. 11 / Atomic Structure Paradigm Shift
Pg. 12 / Current Atomic Structure Paradigm
Pg. 12-13 / Protons, Neutrons and Electrons
Pg. 13-14 / Isotopes (assignment on pg. 25)
Pg. 15-16 / Average Atomic Mass (assignment on pg. 26)
Pg. 17-18 / Emission of Light
Pg. 18-19 / Orbitals
Pg. 20-21 / Electron Configuration (assignment on pg. 27)
Pg 21-22 / Valence Electrons
Pg. 23 / Lewis Dot Diagrams (assignment on pg. 28)
Pg. 29 / Unit 2 Review Questions

History of Chemistry

Democritus (~460 BCE)
First to propose that matter is made up of small indivisible particles, which he called atoms (Means ______in greek).

Aristotle (~300 BCE)

Declares the existence of only four elements: ______, ______, ______, ______. All matter is made up of these four elements and matter had four properties: hot, cold, dry and wet.

Alchemists (300BCE- 1650)

Attempted to change lead and other metals to ______, discover a universal solvent and discover a life-prolonging elixir.

Alchemists used plant products and ______compounds to treat diseases.

Lavoisier, A. L. (1743-1794)

Renamed the "dephlogisticated air" ______when he realized that the oxygen was the part of air that combines with substances as they burn. He demonstrated the conservation of ______(matter can be neither created nor destroyed) in a chemical reaction and defined the difference between an element and a compound. Called the "Father of Modern Chemistry".

Dalton, John (1766-1844)
The first great chemical theorist; proposed atomic theory. He proposed that each element is made up of tiny particles called atoms, the atoms of a given element are ______, chemical compounds form when atoms ______with each other and chemical reactions involve reorganization of the atoms, which changes in the way they are bound together.

Avogadro, A. (1776-1856)
Proposed principle that equal volumes of gases contain the same number of ______. The number (6.02 x 1023 for 22.41 litres of any gas) is a fundamental constant that applies to all chemical units.
Berzelius J.J. (1779-1850)
Classified minerals chemically; discovered and isolated many elements (Se, Th, Si, Ti, Zr); coined the terms isomer and ______; noted existence of radicals; anticipated discovery of colloids.
Mendeléev, D.I. (1834-1907)
Discovered periodicity of the elements and compiled the first ______.
Le Chatelier, H.L. (1850-1936)
Fundamental research on ______reactions (Le Chatelier’s Law), combustion of gases, and metallurgy of iron and steel.
Becquerel, H. (1851-1908)
Discovered ______, deflection of electrons by magnetic fields and gamma radiation. Nobel Prize 1903 (with the Curies).
Thomson, Sir J.J. (1856-1940)
Research on cathode rays resulted in proof of existence of ______, which he found to be negatively charged particles. Believed the atom was a sphere of positive charge with negatively charged particles in it. (1896). Nobel Prize 1906.

Planck (1858 - 1947)
Initiated the study of quantum mechanics when he announced in 1900 his theoretical research into the radiation and absorption of heat/light by a black body. He found that light cannot be converted into ______(energy) by any arbitrary amount, but only as discrete packets which he called quanta (known as ______today).
Curie, Marie (1867-1934)
Discovered and isolated ______; research on radioactivity of uranium. Nobel Prize 1903 (with Becquerel) in physics; in chemistry 1911.

Robert Millikan (1909)
Discovered the ______of an electron by introducing charged oil droplets into an electrically charged field. The charge of the electron was found to be 1.602E-19 coulombs. Using Thomson's mass ration, Millikan found the mass of one electron to be 9.11E-28 grams. Millikan received the 1932 Nobel Prize in Physics for this discovery.
Haber, F. (1868-1924)
Synthesized ______from nitrogen and hydrogen, the first industrial fixation of atmospheric nitrogen (the process was further developed by Bosch). Nobel Prize 1918.

Rutherford, Sir Ernest (1871-1937)
First to prove radioactive decay of heavy elements and to carry out a transmutation reaction (1919). Discovered half-life of radioactive elements. Rutherford tested Thomson’s ideas that the atom was composed of positive and negative charges and that the atom was a solid mass of these particles. If this model were true, any particles shot at the atom should be deflected by it. If the negative and positive charges were in some arrangement that left ______in the atom, particles shot at the atom might be able to pass through them. In 1909, Rutherford set a fellow scientist, Hans Geiger, and a student, Ernest Marsden, to work on this problem. They observed that while most of the particles passed through the foil with little or no deflection, some were deflected to a great degree. The data collected from this experiment showed the atom had empty space and positively charged ______. Nobel Prize 1908.

Lewis, Gilbert N. (1875-1946)
Proposed electron-______theory of acids and bases; authority on thermodynamics.
Niels Bohr (1885-1962)
Best known for the investigations of atomic ______and also for work on radiation, which won him the 1922 Nobel Prize for physics. Bohr adapted Rutherford’s model of the atom to include ______levels which the electrons orbit. This model of the atom explained the emission spectra of the hydrogen atom.
Chadwick, Sir James (1891-1974)
Discovered the ______(1932) Nobel Prize 1935.

Heisenberg, W.K. (1901-1976)
Research in quantum mechanics resulting in development of the ______l theory of chemical bonding. Stated Uncertainity Principle. Nobel Prize 1932.

Erwin Schrodinger and W. K. Heisenburg (1920’s)

Developed probability functions to determine the regions or ______in which electrons would most likely be found.

de Broglie, L. (1924)

Hypothesized that the electrons in Bohr’s model were confined to discrete orbits because they had the properties of standing waves. This theory is known today as the Principle of Complementarity: Waves and particles represent complementary aspects of the same phenomenon. This means ______phenomena such as light can also have the properties of particles, and ______phenomena such as the constituents of atoms can also have the properties of waves.

Scientists now believe that the basic components of matter are ______ and ______. Ideas about matter have come a long way since Aristotle was arguing against Democritus' idea of indivisible pieces of matter he called atoms.

The Periodic Table

About the periodic Table

What is the periodic table?

· A way to organize ______

· Contains all elements ever discovered or ______

Development of the Periodic Table:

· The periodic table was developed by ______(Russian Chemist). He recognized trends in properties of elements when organized by ______.

· He used these ______to organize the periodic table.

· He was then able to use the periodic table to ______the properties of elements that had not yet been discovered or created.

How is the periodic table organized?

· The periodic table is organized by increasing ______number.

· It is organized into families and periods. ______are the horizontal rows of the periodic table, and ______(or groups) are the vertical rows of the periodic table. Most elements in a family have similar ______.

In the Periodic Table, strontium is directly below calcium and above barium. From the following physical properties of calcium and barium, predict some of the properties of strontium.

Element / Appearance / Density / Melting point / Boiling point
Calcium / Silvery metal / 1.55 g/cm3 / 850°C / 1493°C
Strontium
Barium / Silvery metal / 3.50 g/cm3 / 710°C / 1637°C

We would expect strontium to be a silvery metal with a density of ______. It should melt at about ______and boil at about ______. In fact, strontium is a silvery metal with a density of 2.58 g/cm3, a melting point of 775°C and a boiling point of 1367°C.

The symbols:

· The symbols used for the periodic table come from the ______of the element, but sometimes the symbol comes from the name of the element in another language.

Element / Symbol / Latin Name / Element / Symbol / Latin Name
Antimony / Sb / Stibium / Potassium / K / Kalium
Copper / Cu / Silver / Ag / Argentum
Gold / Au / Aurum / Sodium / Na / Natrium
Iron / Fe / Ferrum / Tin / Sn / Stannum
Lead / Pb / Tungsten / W
Mercury / Hg / Hydragyrum / (German)

· The symbols for the elements are always 1 or 2 letters (except for 110+), where the first letter is always ______case and the second letter is always ______case.

What else is on the periodic table?

· The periodic table comes in different forms, often with different types of information. Some of the information available is: Symbol, name, average atomic mass, molar mass, atomic number, oxidation states, picture of the elements, solid liquid or gas, metal or non-metal… and more

Let’s look at a few different types of periodic tables.

Labels

Periods and groups

· 1 Alkali metals, 2 alkaline earth metals, transition metals, rare earth metals, halogens, noble gases

Metals, metalloids, non-metals

· Properties of metals:

· Good conductors of ______and ______

· High density (heavy for their size)

· High melting point

· ______(most metals can be drawn out into thin wires)

· ______(shininess)

· ______(bendable- most metals can be hammered into thin sheets)

· ______

· Properties of non-metals:

· ______conductor of heat and electricity

· ______(breaks easily)

· Not ductile

· No luster (dull appearance)

· Not malleable

· Low ______

· Low ______point

· Properties of metalloids:

· Can be shiny or dull

· ______

· Ductile

· Malleable

· Conduct heat and electricity better than non-metals but not as well as metals

Solids, liquids and gases (at room temperature)

Diatomic these are elements that are found to be bonded in ______(with itself in nature) example:

Precious metals- These are metals that are found ______in nature (not bonded with anything)

Man made elements- These are elements that are not found in ______, but developed by scientists

Label the periodic table

Periods and Groups:

H / He
Li / Be / B / C / N / O / F / Ne
Na / Mg / Al / Si / P / S / Cl / Ar
K / Ca / Sc / Ti / V / Cr / Mn / Fe / Co / Ni / Cu / Zn / Ga / Ge / As / Se / Br / K
Rb / Sr / Y / Zr / Nb / Mo / Tc / Ru / Rh / Pd / Ag / Cd / In / Sn / Sb / Te / I / Xe
Cs / Ba / La / Hf / Ta / W / Re / Os / Ir / Pt / Au / Hg / Tl / Pb / Bi / Po / At / Rn
Fr / Ra / Ac / Rf / Db / Sg / Bh / Hs / Mt / Ds / Rg / Uub / Uut / Uuq / Uup / Uuh / Uus / Uuo
Ce / Pr / Nd / Pm / Sm / Eu / Gd / Tb / Dy / Ho / Er / Tm / Yb / Lu
Th / Pa / U / Np / Pu / Am / Cm / Bk / Cf / Es / Fm / Md / No / Lr

Metals, Non Metals Metalloids:

Solids Liquids and Gases:

Diatomic Elements, Precious Metals & Man Made Elements:

Trends in the periodic table:

Atomic radius:

· As you go across the periods the atomic radius ______because the number of protons increase to there is a stronger positive pull in the nucleus. This means the electrons are pulled in ______to the nucleus. As you move down the families or groups the radius ______because there are more orbitals in the atom and the electrons cannot be ______in as close.