Chemical BondingChemical Bonding & &

CompoundsCompounds

MoleculeMolecule – a – a particleparticle made up of 2 or more atoms made up of 2 or more atoms bonded togetherbonded together

CompoundCompound – a – a substancesubstance made up of 2 or more made up of 2 or more elements bonded togetherelements bonded together

IonsIons - atoms with different numbers of electrons - atoms with different numbers of electrons

(makes them electrically charged & opposites attract.)(makes them electrically charged & opposites attract.)

Chemical bonding occurs when electrons are: Chemical bonding occurs when electrons are: gainedgained, , lostlost, or , or sharedshared

FormulasFormulas tell the type and number of atoms in a tell the type and number of atoms in a compound. Ex: water - Hcompound. Ex: water - H22O (2 hydrogen, 1 oxygen) O (2 hydrogen, 1 oxygen)

salt - NaCl (1 Sodium , 1 Chlorine)salt - NaCl (1 Sodium , 1 Chlorine)Compounds have characteristics that differ from the individual Compounds have characteristics that differ from the individual elements. ex: H & O are highly combustible gasses; whereas, elements. ex: H & O are highly combustible gasses; whereas, HH22O is not. Sodium is highly explosive in water & chlorine is a O is not. Sodium is highly explosive in water & chlorine is a

green poisonous gas; whereas, green poisonous gas; whereas,

salt is edible and dissolves in water.salt is edible and dissolves in water.

Law of Conservation of Matter: Law of Conservation of Matter: Matter is neither Matter is neither createdcreated nor nor destroyeddestroyed, it remains the same , it remains the same or is rearranged.or is rearranged.

IonicIonic bonds: formed by gaining or losing electrons; then bonds: formed by gaining or losing electrons; then opposites attractopposites attract

Characteristics of ionic compounds include:Characteristics of ionic compounds include: crystal shape, high melting point, & crystal shape, high melting point, &

high electrical conductivity.high electrical conductivity.

CovalentCovalent bonds: formed by sharing electrons bonds: formed by sharing electronsCharacteristics of covalent compounds: Characteristics of covalent compounds:

low melting & boiling points, and low melting & boiling points, and poor conductors of electricity.poor conductors of electricity.

Ionic and covalent bonding animation – YouTubeIonic and covalent bonding animation – YouTube

Covalent molecules can form single bonds Covalent molecules can form single bonds (share 1 pair of electrons), double bonds (share 1 pair of electrons), double bonds

(share 2 pairs), or triple bonds (share 3 pairs). (share 2 pairs), or triple bonds (share 3 pairs).

Polar molecules having unequal Polar molecules having unequal sharing of electrons (ex. Hsharing of electrons (ex. H22O) O)

Nonpolar molecules have equal Nonpolar molecules have equal sharing of electrons. (ex. COsharing of electrons. (ex. CO22))

(ex. CO)(ex. CO) Polar molecules melt at Polar molecules melt at

higher temps than nonpolar.higher temps than nonpolar.

OxidationOxidation number tells how many electrons are number tells how many electrons are

gained, lost, or shared to become stablegained, lost, or shared to become stable All metallic elements, plus Hydrogen & BoronAll metallic elements, plus Hydrogen & Boron tend to lose tend to lose electrons when bonding with nonmetals. electrons when bonding with nonmetals.

(they have few valence electrons, (they have few valence electrons,

so they lose all of their valence electrons)so they lose all of their valence electrons)Nonmetals tend to gain electrons when bonding with metals. Nonmetals tend to gain electrons when bonding with metals.

(they have many valence electrons, they will gain (they have many valence electrons, they will gain enough to equal 8. example: has 5, gains 3)enough to equal 8. example: has 5, gains 3)

Nonmetals tend to share electrons when bonding with Nonmetals tend to share electrons when bonding with nonmetals. nonmetals. (ex; covalent bond H(ex; covalent bond H22O: 1 + 1 + 6 = 8)O: 1 + 1 + 6 = 8)

Noble Gases do not form chemical bonds because they already Noble Gases do not form chemical bonds because they already have a full valence shell have a full valence shell (8),(8), so they neither gain, lose, nor so they neither gain, lose, nor share electrons.share electrons.

OrganicOrganic Compounds contain carbon. Compounds contain carbon.

Carbon bonds easily because it has Carbon bonds easily because it has 44 electrons electrons in its outer shell, so it can form in its outer shell, so it can form 44 separate separate covalent bonds.covalent bonds.

4 groups of organic compounds in living things4 groups of organic compounds in living things

1.1. Carbohydrates: – Carbohydrates: – composed of composed of

CC, , HH, & , & OO in a 1:2:1 ratio. in a 1:2:1 ratio.

2. Lipids: (fats) – composed of 2. Lipids: (fats) – composed of long chains of long chains of CC, , HH, & , & OO..

3. Proteins – composed of 3. Proteins – composed of CC, , HH, , OO, & , & NN. .

4. Nucleic Acids – 4. Nucleic Acids – composed of composed of

CC, , HH, , OO, , NN, & , & PP

WaterWater (H (H22O ) is an essential compound for all life on O ) is an essential compound for all life on

Earth.Earth.

Due to its unique structure, water has very good Due to its unique structure, water has very good adhesion_adhesion_(water sticks to surfaces) and (water sticks to surfaces) and

cohesion cohesion (water sticks to water). (water sticks to water).

This aids in capillary action in plant stems/roots. This aids in capillary action in plant stems/roots.

Water is often referred to as the universal Water is often referred to as the universal solventsolvent because of its ability to dissolve many different because of its ability to dissolve many different substances. Since water molecules are polar they substances. Since water molecules are polar they attract ions and the charged parts of molecules.attract ions and the charged parts of molecules.

A Wet Towel In Space Is Not Like A Wet Towel On EarthA Wet Towel In Space Is Not Like A Wet Towel On Earth : :

KrulwichKrulwich Wonders... : NPR Wonders... : NPR