Drawing Atoms

1
Drawing Atoms Chemical Bonding

• January 4, 2016

2
Electron Energy Levels
energy levels

• Electrons are arranged in within the electron
  cloud.
• Each energy level can hold a certain maximum
  number of electrons.
• First level ____
• Second level ____
• Third level ____

2
8
8
3
Drawing an Atom

• Fluorine Atom (F)

How many electrons does a Fluorine atom have?
_______
9 P 10 N
9
4
Electron Energy Levels
Valence
most stable

• The atoms have the outermost energy level
  filled.
• Atoms in which the outermost energy level is
  filled does not easily gain or lose electrons,
  therefore they do not easily form compounds with
  other elements.
• ____________ electrons represent the number of
  electrons in the outer energy level.

5
Drawing an Atom
Im Stable

• Neon Atom (Ne)

How many electrons does a Neon atom have? _______
10 P 10 N
Go away, I dont want to BOND with anyone.
10
6
CHEMICAL BONDS

• When two or more elements come together, they
  form a compound.
• Compounds are held together by forces called
  chemical bonds.
• Atoms can form chemical bonds by sharing
  electrons or by transferring electrons from one
  atom to another.

7
Types of Bonds

• When a compound is formed through the transfer of
  electrons, this is called an ionic bond.
• Most ionic compounds are formed by the transfer
  of electrons from a metal to a nonmetal.
• When an atom loses an electron to move to another
  atom, it ends up with more protons than
  electrons. This results in an overall __________
  charge.

positive
8
Types of Bonding

• When an atom gains an electron from another atom,
  it ends up with more electrons with protons.
  This results in an overall ___________ charge.
• Ions electrically charged atoms.
• (Ex) Na or Cl-

negative
9
Cl Na
Now, the Na gives or transfers its one extra
electron to Cl
11P 12N
17P 18N
Now everyone is happy
10
Types of Bonding

• Covalent bond a bond based on the attraction
  between atoms that share electrons. (Ex)
  Water H2 O

11
Covalent Bonding (Water Molecule)

• H2O

1 P
Hydrogen
8 P 8 N
Hydrogen
1 P
Oxygen
12
Review Questions

• In water, how many electrons does oxygen share
  with each hydrogen atom?
• What kind of bond is this?
• How many valence electrons does sodium have?
• How many valence electrons does chlorine have?
• Describe what happens when sodium bonds with
  chlorine.

One
Covalent Bond
One
Seven
13
Review Questions

• What kind of bond is formed between Na and Cl?
• After the bond between sodium and chlorine forms,
  how many electrons does sodium have in the
  resulting outer layer?
• What is the charge of a teaspoon of salt (NaCl)
  crystals? Explain.

An Ionic Bond
Eight
Neutral