Presentation is loading. Please wait.

Presentation is loading. Please wait.

Ch. 11.4 Notes---Atomic Properties and the Periodic Table Valence Electrons and Electron Dot Notations What are “valence electrons”? These are the electrons.

Similar presentations


Presentation on theme: "Ch. 11.4 Notes---Atomic Properties and the Periodic Table Valence Electrons and Electron Dot Notations What are “valence electrons”? These are the electrons."— Presentation transcript:

1 Ch Notes---Atomic Properties and the Periodic Table Valence Electrons and Electron Dot Notations What are “valence electrons”? These are the electrons in the _________-_______ energy level (or shell). These are responsible for chemical bonding. All of the other electrons are called “core electrons”. They will be “___” electrons and “___” electrons only. Counting Valence Electrons Group A # = number of valence electrons (only exception Helium = __ e - ’s) Examples: Ca = __ e - ’sNitrogen = __ e - ’sArgon = __ e - ’s d-block and f-block = ___valence e - ’s outermost s p

2 Drawing Valence Electrons “Electron-dot notation”: Electrons will be represented as dots located around the symbol of the element in the pattern shown below. Examples: Nitrogen = Hydrogen = (important exception.... Carbon = ) X NH C

3 The Development of the Periodic Table _________________________: constructed the 1 st periodic table Features of Mendeleev’s Periodic Table He left ______ _________ for “missing elements”. Later when these elements were discovered, he filled in the gaps. He arranged the elements in columns and rows according to their __________________. Elements with similar properties were in the same horizontal row. He was able to accurately ___________ the properties of the missing elements based on the properties of the elements in similar _______. He ordered the elements by increasing __________ ___________. Dmitri Mendeleev blank spaces properties predict rows atomic mass

4 Features of the Modern Periodic Table In 1913, Henry ______________ determined the atomic number, (# of ___), of the elements. – He then arranged the elements in the periodic table by increasing atomic ____________. – This switched the position of some elements. This is how the modern periodic table is arranged today. Horizontal Rows = ____________ or Series Vertical Columns = ____________ or Families Elements in the same _________/_________ have similar properties. Moseley number p+p+ Periods Groups groupsfamilies

5 Figure 11.35: Classification of elements as metals, nonmetals, and metalloids.

6 Parts of the Periodic Table Metals: located to the _______ of the dark zig-zag line running through the “p-block”. This includes the elements in the ___-block. Properties of Metals – shiny surface – ______________ (you can pound it into a flat sheet) – ______________ (you can draw it into a thin wire) – good _______________ (heat/electricity travels through it easily) left f malleable ductile conductors

7 Parts of the Periodic Table Nonmetals: located to the ___________ of the dark zig-zag line. Properties of Nonmetals – _______ surface – ______________ – good _______________ (or poor conductors) Metalloids: located on the border of the dark zig-zag line. Examples: Silicon & Germanium Properties of Metalloids – ___________________ right dull brittle insulators semiconductors(Used in computer chips) sulfur

8 Parts of the Periodic Table d-block metals: “_________________ metals” f-block metals: “Inner-transition metals” or “____________ metals” Special Group/Family Names Group 1A: “_________ metals” – React with _________ to form a base Group 2A: “________________ metals” – Compounds are used in batteries Group 7A: “_________________” – Used in some light fixtures Group 8A (or 0 or 18): “_______ gases” – Don’t form compounds (_________) transition rare-earth Alkali water Alkaline-earth Halogens Noble inert

9 Parts of the Periodic Table Inner- transition metals

10 Trends in the Periodic Table Atomic Size (Atomic Radius) (See Fig ) Moving Down a Group= the size of the atoms ________________ – Why? You are adding ________ electrons to higher and higher energy levels (farther and farther out.) Moving Across a Period= the size generally ______________ – Why? You are adding more e - and p + to the same energy level. This causes more ______________ of opposite charges and it __________ the electron cloud inward. increases more decreases attraction pulls

11 Figure 11.36: Relative atomic sizes for selected atoms.

12 Trends in the Periodic Table Atomic Size vs. Ion Size (See Figure 12.8) Cation = (___) charged atom created by ___________ e-’s. – Cations are ______________ than the original atom. – _____________ generally form cations. Anion = (___) charged atom created by _____________ e-’s. – Anions are ____________ than the original atom. – _______________ generally form anions. + removing smaller Metals − adding larger Nonmetals

13 Trends in the Periodic Table Atomic Size vs. Ion Size

14 Figure 12.8: Relative sizes of some ions and their parent atoms. picometers

15 Ionization Energy Ionization energy is the energy required to _______________ the outer most electron in an atom. Moving Down a Group= _______________ (less energy is needed) – Why? You are trying to remove an electron that is farther and farther out (for larger and larger atoms). These e - ’s are not as ________________to the nucleus. – In general, the larger the atom, the ____ attracted it is to its e - ’s. Trends in the Periodic Table remove decreases attracted less

16 Ionization Energy Moving Across a Period= generally ________________ – Why? Moving across a period takes us from metals to nonmetals. More ionization energy is needed for ______________ compared to __________. – Also, since metals generally form _________, it won’t take as much energy to remove it’s outer most electron. – Remember that as you move across the period, the atoms get _________ and therefore ______ attracted to the electrons. Trends in the Periodic Table increases nonmetalsmetals cations smallermore

17 First Ionization Energies

18 “Successive Ionization Energies” “Successive Ionization Energies” means the energy required to remove a _____ or a _____ electron from an atom. – Removing more and more e - ’s requires ______ and ______ energy. – Why? The remaining e - ’s are more _________ _________ to the nucleus. Trends in the Periodic Table 2 nd 3 rd more tightly bound

19 Electronegativity (See Figure 12.4) Electronegativity is a relative value (from_________) which compares how much an atom is attracted to the e - ’s in a ____________ bond. Moving Down a Group= generally ______________ (less attraction) – Why? The bonded electron is farther and farther out. These e - ’s will not be as attracted to the larger and larger atoms. Trends in the Periodic Table 0 – 4.0 chemical decreases

20 Figure 12.4: Electronegativity values for selected elements.

21 Electronegativity Moving Across a Period= generally _________________ – Why? Again, the atoms are getting ________ so they are _______ attracted to the bonding electrons. – Also, moving across a period takes us from metals to nonmetals. Since nonmetals generally form _________, they tend to __________ e - ’s anyway, and this makes them ________________ attracted to e - ’s when forming a chemical bond. – ___________ __________ are not listed in Figure 12.4 since they do not ________ _____________ ! Trends in the Periodic Table increases smaller more anions gain highly Noble gases form compounds

22 Determining the Ion Formed Atoms try to achieve a ________ ______ configuration when forming an ion. (This makes them more stable.) – Locate the nearest noble gas and count how many “places” it is away, but remember that you can skip over the d-block!! – This amount will be the same as the # of e - ’s either gained or lost by the atom when forming an ion. Practice Problem: How many electrons are gained or lost when forming an ion from the following elements? a) Magnesium: ____ (gained or lost) b) Iodine: ____ (gained or lost) c) Gallium:____ (gained or lost) d) Boron:____ (gained or lost) noble gas 21 33


Download ppt "Ch. 11.4 Notes---Atomic Properties and the Periodic Table Valence Electrons and Electron Dot Notations What are “valence electrons”? These are the electrons."

Similar presentations


Ads by Google