A Matter PowerPoints There are 3 PowerPoints in this packet. Matter Physical Changes Energy & Heat Transfers
A Matter2 Matter
A Matter3 Matter A pure substance or a mixture Composed of one or more elements that are displayed on the periodic table The periodic table; a tabular way to display all known chemical elements To provide a framework to classify and compare chemical elements Food is matter
Physical Changes Food is matter-A pure substance or mixture
A Matter5 Physical properties Thermodynamics -- effect of change in temperature, pressure, and volume (canning) Heat transfer -- the passage of thermal energy from a hot to a cold body (cooking and cooling) Microwave -- passing microwave radiation through food and water, fat, and sugar so they absorb energy (cooking) Texture Appearance
A Matter6 Why study physical changes? Physical changes are crucial in: Product development Process design Shelf life
A Matter7 Physical changes to matter Physical changes to matter involve: Changing shape/size – crushing ice Changing temperature – boiling ice Changing phase – melting ice
A Matter8 Changing its Shape or Size Chopping Slicing Mashing Grinding
A Matter9 Changing the Temperature Change the temperature of matter without changing its chemical identity – heating and cooling. Examples include pasteurization and rapid cooling.
A Matter10 Changing Phase: Three states of matter are: Solid -- ice Liquid -- water Gas – steam Physical change in the state of matter that does not change the molecular structure.
A Matter11 Changing Its Phase Phase is a physical change in state of matter that does not change the molecular structure. The three states of matter – solid, liquid, and gas.
Energy and Heat Transfer
A Matter13 What Is Energy? Types of energy Mechanical Chemical Electrical Radiant Nuclear
A Matter14 What makes a machine to perform work. Examples include: Hand mixers Water wheel Flour mill Mechanical Energy
A Matter15 Chemical Energy As bonds break or form between atoms, chemical energy is generated. Examples include: Using ice and salt to make ice cream. Digestion of foods.
A Matter16 Electrical Energy Movement of electrons Transported through wires to where needed. Easily changed to heat or mechanical energy. Examples include: Electrical home appliances – stove, refrigerator, dishwasher
A Matter17 Radiant Energy Energy transmitted in the form of waves through space or some medium. Examples: Microwave oven Sun Charcoal grills Gas flames
A Matter18 Nuclear Energy Splitting or combining atoms of certain elements which give off radiation. Examples: X-rays in medicine Nuclear power Irradiation – food preservation
A Matter19 What Is Heat? Definition – An energy transfer from one body to another caused by a temperature difference between the two bodies.
A Matter20 Three Ways Heat is Transferred Conduction Convection Radiation
A Matter21 Conduction Heat (or energy) is transferred by molecular collisions. Example: Cooking foods in an oven.
A Matter22 Convection Heat (energy) is transferred through molecular collisions and and currents. Heat (energy) is more rapid than conduction. Example: Food cooked in boiling water.
A Matter23 Radiation Heat (energy) is transferred by light waves through space. Examples: Sunlight Microwave
A Matter24