10. CONDUCTION
• What is conduction?
• Well, heat is transferred in several different ways:
conduction, convection, and radiation. Regardless of
the method of transfer, only heat can be transferred
because cold is the absence of heat. Conduction is the
transfer of heat from one molecule to another through
a substance. Not all substances conduct heat at the
same speed. Metals and stone are considered good
conductors since they can speedily transfer heat, but
wood, paper, air, and cloth are poor heat conductors.
12. CONVECTION
• Convection is the concerted, collective
movement of ensembles of molecules within
fluids (i.e. liquids, gases) and rheids.
Convection of mass cannot take place in
solids, since neither bulk current flows nor
significant diffusion can take place in solids.
Diffusion of heat can take place in solids, but
is referred to separately in that case as heat
conduction.
14. RADIATION
• In physics, radiation is a process in which energetic
particles or energetic waves travel through a medium or
space. Two types of radiation are commonly differentiated
in the way they interact with normal chemical matter:
ionizing and non-ionizing radiation. The word radiation is
often colloquially used in reference to ionizing radiation
(i.e., radiation having sufficient energy to ionize an
atom), but the term radiation may correctly also refer to
non-ionizing radiation (e.g., radio waves, heat or visible
light). The particles or waves radiate (i.e., travel outward in
all directions) from a source. This aspect leads to a system
of measurements and physical units that are applicable to
all types of radiation.
