Atomic Review and Naming Compounds
description
Transcript of Atomic Review and Naming Compounds
Atomic Review and
Naming Compounds
Electron (e-)orbit/energylevel
Proton (p+)
Neutron (n0)
nucleus
# of p+
p+ + n0
Deuterium Atomic Mass = 2
Atomic Number = 1
Hydrogen Atomic Mass = 1
Atomic Number = 1
Atoms that have the same number of protons but a different number of neutrons are called Isotopes.
H : neutral atom
H+ : positive ion
H- : negative ion
Atoms can either gain or lose electrons
Gain - negatively charged ion. Loses - positively charged ion
Octet rule: atoms react to acquire a full outer shell:
• Give away an e- to another atom.• Take an e- from another atom.• Share an e- with another atom.
Ionic bond
Covalent bond
An ION is an atom that has lost or gained an electron.
Lose e- – positive ion OR cation. (metals)Gain e- – negative ion OR anion. (nonmetals)
+1
+2 -3 -2 -1+3 +4/-4
Remember: The number of the column is equal to the valence electron number. Know that and you figure out the number of electrons lost or gained – the ionic charge
Ionic
NaCl
A compound has different characteristic properties than the atoms which form it.
Covalent
HCl
Diatomic Elements: Elements that are most commonly found in a covalent bond with itself.
I Have No Bright Or Clever Friends
I2 H2 N2 Br2 O2 Cl2 F2
Chemical formula gives the following information:
· The different elements in the compound.· The number of atoms in the compound.
Writing Rule 1: Write the symbol of the metallic element first.
Be Cl
Rule 2:
Place the combining capacity of one element as a subscript of the other element.
Beryllium combines with Chlorine
+ -12
Rule 3: Leave subscripts with a value of 1 out.
Be Cl2 1
Two Naming rules: 1. Write the full name of the metal ion first. 2. Name the non-metal ion dropping the last part of the name and adding the suffix “ide”.
berylliumchloride
Rule 4: Reduce the subscripts if possible.
Mg S
Magnesium combines with Sulfur
Mg S + -22
magnesium sulphide
Transition metals
Transition metals can give away different numbers of electrons.
To avoid confusion:
Brackets are used to show how many electrons the Transition metal is giving away.
Iron (III) chlorideIron (II) chloride
Fe Cl + -12
FeCl2
Fe Cl + -13
FeCl3
Write the name of the ionic compound:
PbO
Pb O+ -
1 2
lead oxide(IV)
+4 -2Remember: Always look at the anion to
see if it has been reduced. If it has, so has the metal.
Covalent Compound:
Contain two or more NON-METAL atoms.
Formed by SHARING valence electrons to fill outer shell – octet rule.
· A molecule is the smallest unit of a covalent compound.
Non-metal + Non-metal = covalent bonding
Prefix Number of Atoms
mono 1di 2tri 3
tetra 4penta 5hexa 6hepta 7octa 8nona 9deca 10
Step 1: first non-metal is named with a prefix to show the number of atoms.
We do not use “mono” for the first non-metal.
nitrogen oxide
N O
Step 2: second non-metal is named with a prefix AND with the “ide” ending.
di
2 4
tetradinitrogen tetroxide
PrefixNumber of
Atoms
mono 1
di 2
tri 3
tetra 4
penta 5
hexa 6
Writing formulas
Step 1: Write the symbol of each element.
Step 2: Use a subscript to show the number of each type of atom given by the prefix.
Do not reduce covalent formulas.
phosphorus oxide
P O di
2 5
penta
PrefixNumber of
Atoms
mono 1
di 2
tri 3
tetra 4
penta 5
hexa 6
Does it have a metal?
NOYES Is it a transition?
• NO charges• NO criss-cross• Use prefixs• Ends in “ide”
YES• Find charges• Reverse Criss-cross• Use Brackets• Ends in “ide”
NO• Find charges• Criss-cross• Ends in “ide”