Important Materials Flashcards
Define a metal
A metal is a substance that is typically solid (except for mercury), shiny, and a good conductor of electricity and heat. Metals are malleable, ductile, and have a high melting point. They tend to lose electrons in chemical reactions, forming positive ions (cations).
Define a non-metal
Non-metals are elements that lack the characteristics of metals. They are typically poor conductors of heat and electricity, are not lustrous, and are often brittle when solid. Non-metals tend to gain electrons in chemical reactions, forming negative ions (anions).
Define a metalloid
Metalloids are elements that have properties intermediate between metals and non-metals. They can exhibit characteristics of both categories, depending on the conditions. For example, silicon is a metalloid that is shiny like a metal but brittle like a non-metal and a semiconductor of electricity.
Properties of a Metal
Good electrical and thermal conductivity
High melting and boiling points
Malleable and ductile
Lustrous (shiny)
Tend to lose electrons and form positive ions
Properties of a Non-metal
Poor electrical and thermal conductivity
Low melting and boiling points
Brittle in solid form
Dull appearance
Tend to gain electrons and form negative ions
Define an alloy
An alloy is a mixture of two or more elements, where at least one element is a metal. Alloys are designed to have enhanced properties compared to the pure metals they contain.
Examples of alloys and their uses
Steel (Iron + Carbon): Used in construction, tools, and automotive industries.
Brass (Copper + Zinc): Used in musical instruments, decorative items, and plumbing fixtures.
Bronze (Copper + Tin): Used in coins, sculptures, and bearings.
What are the different types of steel (composition, differences, uses)
Carbon Steel: Composed primarily of iron and carbon. It’s classified into low, medium, and high carbon steels. Used in construction, pipelines, and machinery.
Stainless Steel: Contains iron, carbon, and chromium (and sometimes nickel). Known for its corrosion resistance, used in kitchen appliances, medical instruments, and cutlery.
Alloy Steel: Includes additional alloying elements like manganese, silicon, and vanadium. Used in automotive parts, power generators, and pipelines.
What is nanotechnology?
Nanotechnology is the manipulation of matter on an atomic, molecular, and supramolecular scale, typically below 100 nanometers. It involves creating and using materials, devices, and systems with novel properties and functions due to their small size.
How small is a nanometre?
A nanometer (nm) is one-billionth of a meter (0.000000001 m). It’s the scale at which atoms and molecules operate.
Hydrophilic vs Hydrophobic
Hydrophilic:
Substances that are attracted to water and can dissolve or absorb water easily.
Hydrophobic:
Substances that repel water and do not dissolve or mix well with water.
What is the pH scale?
The pH scale measures the acidity or basicity of a solution. It ranges from 0 to 14, with 7 being neutral. Values below 7 indicate acidity, and values above 7 indicate basicity (alkalinity).
What is a base?
A base is a substance that releases hydroxide ions (OH-). A base that can dissolve in water is also referred to as alkali. If an alkali is dissolved in water, the solution can be called an alkaline solution.
What is an acid?
An acid is a substance that releases hydrogen ions (H+) into an aqueous solution.
What ways can pH be measured?
Litmus paper: Changes color in acidic or basic solutions.
pH meter: Provides a precise digital measurement.
Universal indicator: Changes color according to the pH level.
Define lusterous
Having a shiny surface that reflects light.
Define malleable
Capable of being hammered or pressed into shape without breaking.
Define ductile
Able to be drawn into thin wires.
