1. Basic Food Chemistry Essential Questions (pgs 79-82)
Why is understanding chemistry essential to food science?
What is an atom?
Identify the parts of an atom.
Draw a model of an atom
What determines which element an atom is?

2. Answers:
To understand why ingredients react the way they do in recipes or formulations
Smallest unit of any elemental substance that maintains the characteristics of that substance
Nucleus, Protons, electrons, neutrons
Student drawing
The number of protons in the nucleus

3. Basic Food Chemistry Essential Questions (pg 79-82)
What is the purpose of the periodic table?
Explain what a “group” and “period” are in the periodic table.
What happens when two molecules of different elements combine?

4. Answers
Classifies elements by relationships; shows how elements relate to and react with each other
Group- columns Periods – rows
Forms a chemical compound

5. Chemical Formulas NaOH HCl CO NaCl
What elements are found in each of these compounds?
FeS
CaCN
KCl
MgN
AlO

6. Chemical Bonding (pgs 83-86)
The force that holds two atoms together
Bonds are formed between electrons
Electrons move in “shells” around the nucleus of an atom
Number of shells in the atom determines the element’s period (row) in Periodic Table

7. Chemical Bonding
Atoms are most stable when its outer shell of electrons is full
If only one electron in outer shell, atom will try to give it away
If only missing one electron in outer shell, atom will try to gain one from another atom

8. Types of Chemical Bonds
Ionic Bonds
Electrons are transferred from one atom to another
Results in positive/negative charge
These substances tend to dissolve in water
Covalent Bonds
One or more pairs of electrons are shared between atoms (ex. Water)

9. The Classification of Matter
Classified into 2 General Categories
Pure Substances
Mixtures

10. Pure Substances Matter in which all of the basic units are the same
Elements
Compounds
Organic (contain carbon or carbon chains)
Inorganic (contain no carbon or only single carbon atoms)

11. Mixtures Substances that are put together but not chemically combined
Example: milk contains calcium and salt;
Homogenous mixture
Uniform distribution of particles
Heterogeneous mixture
Non-uniform distribution of particles

12. Homework 11/5/12 (Due 11/6/12)
At home, search through your refrigerator and cabinets for various food products.
List the food products you find into two categories:
Homogeneous foods
Heterogeneous foods

13. Physical and Chemical Changes Pages 88-91 (Due 11/7/13)
Explain the difference between a physical and a chemical change.
Describe the three phases of physical matter.
Give an example of a permanent physical/chemical change and a reversible physical/chemical change.
Explain the law of conservation of matter. Give an example.