Matter 4.7B Conduct tests, compare data and draw conclusions about physical properties of matter including states of matter, conduction, density and buoyancy

PHYSICAL PROPERTIES A property is a characteristic of an object or material that helps to identify or classify the state of matter. Attribute is a synonym for property.

PHYSICAL PROPERTIES MOSTLY YELLOWHEIGHT RED BOWMASS BLACK CIRCULAR EYES FEELS SMOOTH FLOATS

STATES OF MATTER The forms that matter can take: SOLID LIQUID GAS

solids Definite shape Definite volume

Liquid Takes the shape of its container Definite volume

Gas No definite shape No definite volume

Physical Properties Conduction of heat: The transfer of heat from a warmer object to a cooler object through direct contact

Conduction of heat Think of heat conduction as a relay race. When one end is heated, the molecules begin to vibrate faster heating up. Moving up the object the next molecule begins to vibrate faster heating up. The heat is gradually passed through the object from molecule to molecule. As each molecule begins to vibrate faster transferring the heat a little energy is lost.

Conductors and Insulators Conductors move energy from place to place copper aluminum Insulators stop or slow the flow of energy from place to place rubber wood

Think About It You and your friends are having hot chocolate for an afternoon snack. You put a metal spoon into your cup of hot chocolate and begin to stir it. As you stir the hot chocolate the spoon begins to feel warm. What is happening to the spoon?

Think About It A. Heat from your hand is conducted downward through the spoon. B. Heat from the hot chocolate is conducted upward through the metal spoon. C. Metal spoons are good insulators so it heats up quickly.

And the answer is: B. Heat from the hot chocolate is conducted upward through the metal spoon. The hot chocolate begins to heat the bottom of the spoon. The molecules in the spoon begin to vibrate and heat up. The heat is gradually passed up the object from molecule to molecule, heating the spoon.

Think About It It is important to save energy. The average house loses heat in many ways. Windows lose about 10%, doors 15%, floors 15%, walls 35%, and roof 25%. The house loses heat because…

Choices A. The heat moves from one warm place in the house to another warm place in the house. B. The heat moves from a cooler place in the house to a warmer place outside the house. C. The heat moves from a warmer place inside the house to a cooler place outside the house.

AND THE ANSWER IS: C. The heat moves from a warmer place to a cooler place outside the house. The heat from the house moves to the cooler places outside of the house such as: through floors, windows, doors, roof.

CHALLENGE What can be used to reduce the heat loss from the house? ???????? ??????