Final Flashcards
True or False
The person who came out with the idea that atoms vibrate is Robert Brown and the concept is called Brownian motion
True
True or False
The concept of the atom is 100th and several thousandths of years old
True
True or false
The idea that matter is composed of atoms it goes back to the Greeks in the fifth century B.C
True
True or false
We know of 118 distinct atoms, called the chemical elements. Only 88 elements are found naturally
True
True or false
All materials burn at the same color?
True
True or false
Neil’s Bohr knew that when pure elements were excited by heat or electricity they gave off distinct colors
True e
Who came up with the concept that when an atom is excited, such as during heating, electrons can jump to higher levels. When the electrons fall back to lower energy levels, precise quarta wavelengths (lines) of light
Neil’s Bohr
True or false
In a atom the number of electrons equal the number of neutrons
False -protons
True or false
Aluminum is a solid?
False
True or false
Aluminum is an amorphous liquid?
True
True or false
The type of bond that is in a crystal is a coordinate covalent bond
True
True or false
The type of bond in a crystal is an ironic bond
False
True or false
Metals are generally a single element
False it is a mixture
True or false
Specific gravity is defined by weight it is density of material/ density of water
True
True or false
Density is often expressed as specific gravity, the ratio of the density of the material to the density of water
True
True or false
Every pure metal has a specific melting point
True
True or false
Melting point/ boiling point called coligative properties
True
True or false
Most alloys do not melt completely at a specific temperature
True
True or false
Melting starts when the material has reached a certain temperature, but is not completed until a somewhat higher temperature has been reached. This is a fact of great significance in the welding of steel.
True
True or false
The amount of heat required to raise a unit mass of solid metal one degree in temperature is termed specific heat.
True
How many calories do I have to add to 1cc of water to raise it to 1 centigrade
1
True or false
Silver is a better conductor of heat than aluminum
True
True or false
Silver is a better conductor of heat than steel
True
True or false
The increase in dimensions on a solid body due to an increase in temperature is termed thermal expansion
True
What material does not expand to heat?
Entimity contracts to heat
True or false
By adding carbon to steel the temperature it freezes at is increased
True
True or false
If you add a lot of carbon to steel the freezing temp drops
True
True or false
The ability of the metal to resist pulling force, specifically, to what is termed its tensile strength
True
True or false
yield strength/point is the permanent deformation and force is required to deform a material
True
True or false
Fracture strength is force required to break an object per unit area?
True
True or false
Ductility is how much a material is stretched out with 2 inches of length/ percentage of eleongation in 2”
True
True or false
Hardness is usually defined as the ability of the metal to resist indentation or penetration by another material
True
True or false
Compressive strength is the ability of a material to resist a gradually applied “push”, rather than “pull”, compressing and stressing or push or pull.
True
True or false
Most of the steels have crystals called ferrite, pearlite, and cementite
True
True or false
Steels in the lower part of the range seldom contain pearlite. The carbon usually winds up in particles of iron carbide (cementite) scattered grains of ferrite.
True
True or false
Any steel which contains more than 1.65 % manganese or .60% copper! or a guaranteed minimum amount of any other metal is termed an alloy steel.
True
True or false
The metals most frequently used for alloying purposes are nickel, chromium, molybdenum, vanadium, manganese, and stainless steel
True
True or false
Steel annealed by heating to a temperature above the critical (733 degrees Celsius), so that all the iron will return to the face-centered form called austenite, and then allowing it to cool slowly through the transformation range. Makes it softer and malleable
True
True or false
An intimate mixture of ferrite and cementite known as pearlite
True
Does ferrite have oxygen in it?
Yes it’s iron oxide
If I have a steel that is called a feretic steel what does it have in it?
Chromium with small amount of carbon
What’s the difference between a ferritic steel and martensitic?
Martensitic are similar to ferritic steels in being based on chromium but have higher carbon levels up as 1%. This allows them to be hardened and tempered much like carbon and low -alloy steels
True or false
Steel is tempered by heating it to a temperature below the transformation range and then allowing it to cool at a controlled rate.
True
Can you weld cast iron?
Yes common cast iron cannot be welded but there are weld able cast irons
True or false
The four digit steel numbers- the first two are alloys the last two is the percentage of carbon
True
True or false
If a bolt has 3 lines on the top it is medium carbon Steel
True
True or false
If the bolt is black it is high carbon steel
True
True or false
If there is no lines on the top of the bolt it is low carbon steel
True
True or false
10.9 is metric it’s medium carbon steel
True
How do you make aluminum stronger?
Cole rolling
True or false
Cast irons are good for drilling
True
True or false
The first number of the aluminum tells the percentage of aluminum is 1 copper is 2 and manganese is 3
True w
If you drill steel really fast what’s the danger?
The part where you are drilling the whole is soft which is not good
True or false
Plastic material is any of a wide range of synthetic or semi synthetic organic solids that are moldable and are usually classified by their chemical structure of the polymers backbone and side chains.
True
True or false
Thermoplastic doesn’t change chemical structure
True
What is the difference polypropylene and nylon?
How do you get rid of heat?
How to get rid of heat?
Radiation
Convection
Conduction
Evaporation
