Chap. 6: How Atoms Bond Flashcards Preview

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1

 

Electron-Dot Structures

A shorthand notation of the shell model of the atom, in which valence electrons (outermost electrons, but not full shells) are shown around an atomic symbol. 

Can also be called Lewis Dot Structure.

2

 

Representative Elements

Representative elements fill the "s" and "p" subshells. 

  • "s" =  1 orbital
  • "p" =  3 orbitals

 

Hydrogen (H)  

Group = 1A           

Valence Electrons = 1 

 

Magnesium (M)          

Group = 2A

Valence Electrons = 2

 

Aluminium (Al)          

Group = 3A

Valence Electrons = 3

 

Carbon (C)                  

Group = 4A

Valence Electrons = 4

 

Nitrogen (N)              

Group = 5A

Valence Electrons = 5

 

Oxygen (O)                

Group = 6A

Valence Electrons = 6

 

Iodine (I)                    

Group = 7A

Valence Electrons = 7

 

Argon (Ar)    

Group = 8A

Valence Electrons = 8

 

3

 

Hydrogen (H)

Electron-Dot Structure

4

 

Magnesium (Mg)

Electron-Dot Structure

5

 

Aluminium (Al)

Electron-Dot Structure

6

 

Carbon (C)

Electron-Dot Structure

7


Nitrogen (N)

Electron-Dot Structure

8

 

Oxygen (O)

Electron-Dot Structure

9

 

Iodine (I)

Electron-Dot Structure

10

 

Aluminium (Al)

Electron-Dot Structure

11

 

Ionic Bonds

A chemical bond in which there is an electric force of attraction between two oppositely charged ions.

The transfer of electrons.

Electrostatic forces hold them together.

 

12

 

Naming Compounds

  1. The cation is named first and keeps the element name. It is always written first in the formula.
  2. The anion has the element name as a root with the ending "—ide"

13

 

Naming Transition Metals and Other Metals

Transition metals form more than one cation.

Example:

Fe (iron) can be...

Fe3+              or            Fe2+

Let's say we add both of them to chloride...

Fe3+ + Cl-                     Fe2+ + Cl-

FeCl3                          FeCl2

14

 

Naming Transition Metals and Other Metals

(Roman Numerals)

The Roman numerals in parenthesis are the charges for transition metals and other metals only. When naming a transition or other metal with Roman numerals, make that charge as a subscript at the end of the name.

Example:

Iron (III) Chloride  =  FeCl3

Iron (II) Chloride  =  FeCl2

15

 

What is the formula for aluminium and bromine?

  1. Write down the ions and their charges first. To find the charge of each ion, look at your Ionic Charges Periodic Table. Aluminium (Al) has a charge of +3. Bromine (Br) has a charge of -1. Therefore:  Al3+  and  Br1-.
  2. Switch the charges. Aluminum will switch charges with Bromine. Therefore: Al3+ will turn into Al1-.   Br1- will turn into Br3+.
  3. Combine the elements and drop the 1, and the positive and negative signs in the charges. Turn the charges into a subscript. Therefore, your answer will be: AlBr3

16

 

What is the formula for barium and nitrogen?

  1. Write down the ions and their charges first. To find the charge of each ion, look at your Ionic Charges Periodic Table. Barium (Ba) has a charge of +2. Nitrogen (N) has a charge of -3. Therefore:  Ba2+  and  N3-.
  2. Switch the charges. Barium will switch charges with nitrogen. Therefore: Ba2+ will turn into Ba3-.   N3- will turn into N2+.
  3. Combine the elements and drop the positive and negative signs in the charges. Turn the charges into a subscript. Therefore, your answer will be: Ba3N2

17

 

What is the formula for lead (IV) and sulfur?

  1. Write down the ions and their charges first. To find the charge of each ion, look at your Ionic Charges Periodic Table. Lead (Pb) has already been given a charge of 4. From the table, Sulfur (S) has a charge of +2. Therefore:  Pb4  and  S2+.
  2. Switch the charges. Lead will switch charges with sulfur. Therefore: Pb4 will turn into Pb2+.   S2+ will turn into S4.
  3. Combine the elements and drop the positive and negative signs in the charges. Turn the charges into a subscript. Divide each charge by 2. Therefore, your answer will be: PbS2

18

 

What are the formulas for magnesium oxide, barium bromide, copper (II) chloride and lithium nitride?

  • Magnesium Oxide:  Mg2+O2- = MgO
  • Barium Bromide: BaBr
  • Copper (II) Chloride: Cu2+Cl1- = CuCl2
  • Lithium Nitride: Li3N

19

 

Polyatomic Ions

 

Polyatomic ions are molecular groups that behave as a single unit. An ionically charged molecule.

 

Example:    

Ammonium     NH4+

Acetate           CH3CO2

Nitrate             NO3-

Hydroxide        OH-

Bicarbonate     HCO3-

Cyanide           CN-

Carbonate       CO32-

Sulfate             SO42-

Phosphate       PO43-

 

20

 

What is the formula for copper (II) phosphate?

21

 

What is the formula for sodium cyanide?

22

 

What is the formula for tin (IV) carbonate?

23

 

What is the formula for magnesium hydroxide?

24

 

What is the formula for ammonium nitride?

25

 

What is the formula for chromium (III) sulfate?

26

 

What is the charge of chromium (Cr) in CrCl3?

  1. For the first element (which is a transition metal) Cr (chromium), we do not know the charge yet. That is the element we are trying to find the charge for. So, write Cr as an x.
  2. For the second element (which is a halogen) Cl3 (chlorine), has a charge of -1. There are also 3 of those chlorine molecules (from the subscript 3).
  3. We then multiply subscript 3 by the -1 charge of the chlorine element and add it to chromium (x) and solve. The answer: CrCl3 has a charge of 3.

27

 

What is the charge of copper (Cu) in the formula Cu3PO4?

  1. For the first element (which is a transition metal) Cu (copper), we do not know the charge yet. That is the element we are trying to find the charge for, so we will write that as an x for now. BUT there are 3 copper elements (from the subscript 3). So, we multiply the 3 to x →  3(x) .
  2. For the second element PO4 (phosphate), we know that the charge is -3 from the chart of Polyatomic Ions.
  3. We then add copper to phosphate and solve. The answer: Copper (Cu) has a charge of 1.

28

 

What is the charge of iron (Fe) from Fe2S3?

  1. For the first element (which is a transition metal) Fe2 (iron), we do not know the charge yet. That is the element we are trying to find the charge for. So, write Fe as an x. However, there are 2 of those iron elements (from the subscript 2). So, we multiply 2 to x  →  2(x) .
  2. For the second element (which is a chalcogen) S3 (sulfur), has a charge of -2. There are also 3 of those sulfur molecules (from the subscript 3). 
  3. We then multiply the quantity of 3 by the -2 charge in the sulfur element and add it to iron 2(x) and solve. The answer: Fe2S3 has a charge of 3.

29

 

Writing Lewis Structures

  • Nonmetals sharing electrons form covalent bonds.
  • To fill these shells requires 8 electrons. This is also called the Octet Rule.
  • The goal: to achieve noble gas configuration. Noble gases are stable and have full shells.

30

 

NASU Method

 

N → Total electrons NEEDED to fill all shells (which is 8).

A → ACTUAL number of electrons that are available.

S → SHARED electrons.

( N – A = S )

U → UNSHARED or non-bonding electrons.

( A – S = U )  

 

* Remember: The goal is to fill the valence shell of each atom! *