140 likes | 472 Views
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?. Answers:.
E N D
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?
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
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?
Answers • Classifies elements by relationships; shows how elements relate to and react with each other • Group- columns Periods – rows • Forms a chemical compound
NaOH HCl CO NaCl What elements are found in each of these compounds? FeS CaCN KCl MgN AlO Chemical Formulas
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
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
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)
The Classification of Matter • Classified into 2 General Categories • Pure Substances • Mixtures
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)
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
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
Physical and Chemical ChangesPages 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.