The Periodic Table

1. The Periodic Table • J.W. Dobereiner • _____________ • Groupings of ___ elements with _________________

2. The Periodic Table • In the early 1860’s, about ______ elements were known. • There was no reliable method for measuring the ____________________of atoms. • Different chemists would find different ___________ were being used to represent the same compound

3. The Periodic Table • In September of 1860, at the 1st International Congress of Chemistry, __________________________revealed a method for accurately measuring relative masses of atoms.

4. The Periodic Table • 1863 • John Newlands creates ____________________ • It states that every _____ element in order of increasing atomic mass should have similar properties. • This works for some smaller atoms, but does not work as atoms become ____________________

5. The Periodic Table • Dmitri Mendeleev • He arranged the elements by patterns_________ and by similar properties of elements • He noticed that similarities occurred in elements when they were arranged by ____________________ • He ____________________ in his table for elements that he thought existed but had not been discovered • He could make ____________________predictions about the properties of these elements

6. The Periodic Table • Moseley, who had worked with Rutherford, rearranged the periodic table by increasing numbers of ____________________. This led to using the _____________________as the basis for the organization of the periodic table • The Periodic Law • The law stating that many of the physical and chemical properties of the elements tend to ____________________ ____________________ with increasing atomic number.

7. The Periodic Table • s-block • Group 1 • The ____________________ • ____________________ • Not found __________ in nature • Have ____ outer electron • Tend to lose _____electron in compounds • _________ • ________. They can be easily cut with a knife • Low __________ points • ________ reactive toward the bottom of the group

8. The Periodic Table • Group 2 • The ____________________ Metals • Have ___ outer electrons • ____________________ ____________________ than Group 1 elements • Still very reactive, but _____ reactive than Group 1 elements • Not found freely in nature • More reactive towards bottom of group

9. The Periodic Table • Hydrogen • Has ____ outer electron • Is sometimes considered to be a _________element and at other times is considered to be its own group • It is a _____ at room temperature • If frozen until solid, hydrogen is a _______ • _____% of the atoms in the universe are hydrogen atoms • _____% of the mass of the universe is hydrogen

10. The Periodic Table • Helium • A stable and filled ____________________ places it with the noble gases even though it has only 2 outer electrons. • _____% of the mass of the universe is helium

11. The Periodic Table • d-block • Transition Elements • Sometimes called the transition ______ • Groups _______ • All are ______ • Generally ____________________ ____________________ when compared to s-block elements • _______ as reactive as s-block elements • Some can be found _______ in nature • Tend to have _______ outer electrons • Tend to lose ________ electrons in compounds • Cause colors in ______________ as impurities in crystal structures

12. The Periodic Table • p-block • Groups ________ • ______________ elements-elements in the s and p blocks • Have _____ outer electrons • Elements with 4 or more electrons normally ________ or ______ electrons in compounds • ______________ are found in this region

13. The Periodic Table • Group 17 • The Halogens • ______________ ______________ is the most reactive element • ___ outer electrons • Gain ___ electron to achieve a structure like a noble gas • The word halogen means “______________”

14. The Periodic Table • Group 18 • Noble Gases • ______________ due to filled and stable outer energy level • Very few compounds can be made with ___, ___, and ___. • There are no known compounds using ___, ___, or ___

15. The Periodic Table • Helium- 1868 ______________ discovered it in solar spectra • ______________ confirmed helium on earth in 1895 • Neon- 1898 discovered by ______________ • Argon-1894 discovered by ______________ and ________________________ • Krypton-1898 _____________ • Xenon-1898 ______________ • Radon- 1900 ________________________

16. The Periodic Table • Lanthanides • Mostly discovered in __________ • Elements ________ • Also called ____________________________ • They comprise less than ____% of the earth’s crust • Actinides • Elements ______ • All are ______________ • Elements above 92, Uranium, are ______________ • ______________ elements-synthetic elements that are past Uranium, the last of the naturally occurring elements on the periodic table

17. Periodic Trends • Atomic Radii • ______________ across a period • As the number of _______ increases in atoms across a period, the attractive forces of the nucleus on the electrons in the atom also increase. This increase in ______________ allows the nucleus to pull electrons closer to the nucleus, making for _______atoms. • ______________ down a family • Every new family adds an ______________ where electrons can reside. As more energy levels are added, each outer orbital is ___________ from the nucleus than the last.

18. Periodic Trends • Ionic Radius • Cations • Cations are ___________ ions • Metals tend to ______ electrons and become cations • Cations are ________ than the neutral atom • The _____ amount of force pulls on electrons regardless of how many electrons are present in a given atom. The removal of electrons _____________the amount of pull that is distributed among the remaining electrons, holding the electrons __________ to the nucleus. • Anions • Anions are ___________ ions • ______________ tend to form anions • Anions are _________ than the neutral atom • The same amount of force pulls on electrons regardless of how many electrons are present in a given atom. If electrons are added to the atom, the electrons each feel ______ nuclear pull than they did in the neutral atom and move ______________ from the nucleus, __________________ the atomic radius.

19. Periodic Trends • Valence electrons • Electrons found in the____________sublevels of the outermost energy level • Atoms will gain or lose enough electrons to have an ________ • Metals will lose electrons to have an electron configuration like the ______________, becoming cations • Nonmetals will gain electrons to have an electron configuration like the _______________, becoming anions • The Electron Dot structure shows how many _________ electrons an atom has and how many it will gain or lose as it becomes an ion

20. Periodic Trends • Electronegativity • The measure of an atom’s ability to _____________________in a compound • The lowest value is ______(Cs,Fr) • The highest value is ______(F) • Electronegativity __________ across a period because atoms that tend to gain electrons to become ions will also attract electrons when in a compound • Electronegativity _____________ down a family because atoms that are larger are not as effective at attracting electrons because of the distance that outer electrons will be from the nucleus

21. Periodic Trends • Ionization Energy • The energy required to ___________________________ from an atom • Each electron that is removed results in the next electron being ___________________to remove because each remaining electron is held more tightly. • A huge ___________ in the energy required for removing electrons occurs when the atom’s electron configuration is the same as a ______________. • Ionization Energy _____________ across periods • Ionization Energy _____________ down a family

22. Periodic Trends • Shielding Effect • ________ electrons block some of the ______________ on outer electrons, making them __________ to remove • Shielding effect is ________ across a period since no new energy levels are added to the atom • Shielding effect____________down a family because new energy levels of electrons are added with each new row on the periodic table

23. Periodic Trends • Electron Affinity • The energy change when a neutral atom ______________ an electron • Can be ______________ (absorbing energy) or ______________ (releasing energy) • Electron Affinity ______________ across a period • Electron Affinity ______________ down a family

24. Periodic Trends