Chemistry NotesLindstrom 2010

Why Study Chemistry in Biology?

Banana Cell with Starch Granules

The Size of an Atom

I. Matter

1. Humans and organisms and everything around them are made of MATTER

2. Matter is made up of chemical ELEMENTS

3. Pure substances that cannot be broken down into SIMPLER substances.

4. About 25 elements are essential to life…. 96% of your body is made up of CARBON, Oxygen, HYDROGEN, and Nitrogen.

I. Matter5. All elements in the same column

GROUP have the same # of VALENCE ELECTRONS

6. All elements in the same row PERIOD have the same # of ORBITALS

1. 1. 3 Parts3 Parts: :

Location of particlesLocation of particles: protons + neutrons = nucleus: protons + neutrons = nucleus

electrons = rotate around nucleuselectrons = rotate around nucleus

Protons +

Neutrons 0

Electrons -

III. ATOMS

III. ATOMS

2. Atomic # = # of protons

3. # protons = # electrons

4. Atomic Mass =

(#) of protons + (#) of neutrons

III. ATOMS

5. If you change the 5. If you change the

number of number of protons protons, ,

you change theyou change the

element name.element name.

II. Compounds

1. Define: groups of two or more elements that

are bonded together

2. ex: H2O, CO2, NaCl

3.Compound properties are different from individual elements

4.Covalent compounds happen when the atoms share the electrons

5. Ionic compounds happen when electrons are donated from one atom to another

1.1. Different forms of the same element, have the same # of Different forms of the same element, have the same # of protons, but different # of neutronsprotons, but different # of neutrons

IV. ISOTOPES

2. Some can be radioactive!!

3. Useful for:

* Treating cancer, bone imaging- 99Tcm

* Fuel/energy- nuclear reactors

* Dating fossils

* Irradiating food

IV. ISOTOPES

IV. ISOTOPES

4. Electrons belongs to certain energy levels

1st orbital- 2 ELECTRONS

 

2nd orbital- 8 ELECTRONS 

V. Bonding1. Atoms want to fill their outer energy levels to be

HAPPY

2. In order to do this, they will meet up with other atoms and either share or exchange electrons

This is a covalent bond. Electrons are SHARED.

1. Atoms EXCHANGE electrons, becoming

POSITIVELY or NEGATIVELY charged

2. This attraction brings them TOGETHER

3. Ex: Na+ and Cl-

VI. IONIC BONDING

VII. COVALENT BONDING

1. Atoms SHARE electrons so that both atoms

fill their outer energy level

2. Elements can only use electrons from their

OUTER ORBITAL to bond

with other elements

3. Carbon can form FOUR (4) covalent bonds

PHYSICAL CHANGE

• Describe:Describe:

A physical change does not produce a new substance. A physical change does not produce a new substance. Changes in phase (melting, freezing, vaporization, Changes in phase (melting, freezing, vaporization, condensation, sublimation) are physical changes. condensation, sublimation) are physical changes.

• 3 examples:3 examples:

crushing a cancrushing a can

melting an ice cubemelting an ice cube

breaking a glass bottlebreaking a glass bottle

CHEMICAL CHANGE

• Describe Describe

Chemical changes take place on the molecular level. A Chemical changes take place on the molecular level. A chemical change chemical change produces a new substanceproduces a new substance. .

2. 3 examples:2. 3 examples:

combustion (burning)combustion (burning)

cooking an eggcooking an egg

rusting of an iron panrusting of an iron pan

VIII. CHEMICAL REACTIONS

1. Define reactants: the ingredients into a chemical reaction

2. Define products: the results of a chemical reaction

H2 + O -- H2O