covalent and ionic compounds
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Covalent and Ionic Compounds. SNC1D. Different ways for atoms to combine…. Metal + Non-Metal form compound made up of charged particles that become ions by gaining or losing electrons Non-Metal + Non-Metal Electrons are shared between atoms Metal + Metal - PowerPoint PPT PresentationTRANSCRIPT
Covalent and Ionic Compounds
SNC1D
Different ways for atoms to combine…• Metal + Non-Metal
– form compound made up of charged particles that become ions by gaining or losing electrons
• Non-Metal + Non-Metal
– Electrons are shared between atoms
• Metal + Metal– Alloys created by melting two or more metals and
then mixing them
Molecular Compounds
• Two non-metals combine to form a covalent bond whereby electrons are shared between atoms
• By sharing electrons, each atom will have a stable octet
• What is the difference between an ionic bond and a covalent bond?
- An ionic bond is a chemical bond whereby one atom loses electrons to become a positive ion and another gains electrons to become a negative ion- A covalent bond involves the sharing of electrons between atoms in a molecule
Examples of molecular compounds:
• Carbon monoxide• Carbon dioxide• Nitrogen trifluoride• Sulfur hexafluoride
Naming molecular compounds: # of atoms prefix
1 mono-
2 di-
3 tri-
4 tetra-
5 penta-
6 hexa-
7 hepta-
8 octa-
9 nona-
10 deca-
-Add the appropriate prefix depending on the number of each of the atoms in the compound
-If there is only one of the first element in the formula, the mono- prefix is dropped
Write the names for the following molecular compounds:
CCl4
PCl3
NBr3
H2S
H3P
Molecular Elements• Atoms that exist in pairs in nature
• Referred to as diatomic molecules and there are seven
H2, N2, O2, F2, Cl2, Br2, I2
Counting elements in molecules…
NaHCO3 (baking soda)
How many elements does this compound contain?
How many atoms of each element are in baking soda?
What about CH3COOH? (vinegar)
Different ways for atoms to combine…• Metal + Non-Metal
– form compound made up of charged particles that become ions by gaining or losing electrons
• Non-Metal + Non-Metal– Nucleus of one atom forms strong attraction to valence electron
of another atom– “tug of war” for electrons occurs, but neither atom wins – Instead, the two atoms share each other’s electrons, resulting in
a what we call a covalent bond that holds the atoms together • Metal + Metal
– Alloys created by melting two or more metals and then mixing the
– Different from compounds because they are solutions of metals and atoms are not chemically joined
IONIC COMPOUNDS(metal + non-metal)
• Ionic compound: a compound that consists of positively and negatively charged ions
• Atoms want to be stable• In ionic compounds, atoms become stable by either
gaining or losing electrons to accomplish a full outer shell
• An ionic bond is created
Important terms…
• Ion: a particle that has either a positive or a negative charge
• Cation: a positively charged ion
• Anion: a negatively charged ion
• What would have to happen to a lithium atom in order for it to become chemically “stable”?
• What could it join with in order to accomplish this?
Bonding Between Alkali Metals and Halogens
FLUORINE CHLORINE BROMINE IODINE
LITHIUM LiF LiCl LiBr LiI
SODIUM NaF NaCl NaBr NaI
POTASSIUM
KF KCl KBr KI
Naming:-The name of the metal does not change-the name of the non-metal takes an “ide” ending
Ex. NaCl Sodium chloride
Mg
vvvv
vvvv
Cl
Cl2+
1-
Ca ClNeeds to lose 2 electrons
Needs to gain 1 electron
CaCl2
Bonding between Alkaline Earth Metals and Halogens
FLUORINE CHLORINE BROMINE IODINEBeryllium
MagnesiumCalcium
BeF2 BeCl2 BeBr2 BeI2
MgF2 MgCl2 MgBr2 MgI2
CaF2 CaCl2 CaBr2 CaI2