Chemistry Flashcards
Meaning of opaque to describe physical properties
Opaque objects block light from travelling through them. Most of the light is either reflected by the object or absorbed and converted to thermal energy. Materials such as wood, stone, and metals are opaque to visible light.
Meaning of transparent to describe physical properties?
allowing light to pass through so that objects behind can be distinctly seen.
Meaning of translucent to describe physical properties?
Translucent means that light may pass through that material but images on the other side of that material are not clearly visible
Meaning of malleable to describe physical properties
Malleability describes the property of a metal’s ability to be distorted below compression. It is a physical property of metals by which they can be hammered, shaped and rolled into a very thin sheet without rupturing.
Meaning of ductile to describe physical properties
Ductility is the ability of a material to be drawn or plastically deformed without fracture
Meaning of explosive to describe chemical properties?
An explosive is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure.
Meaning of flammable to describe chemical properties?
Flammability is the ability of a chemical to burn or ignite, causing fire or combustion.
Meaning of reactive to describe chemical properties?
In chemistry, reactivity is a measure of how readily a substance undergoes a chemical reaction.
Meaning of toxic to describe chemical properties?
Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism.
Meaning of corrosive to describe chemical properties?
Corrosives are materials that can attack and chemically destroy exposed body tissues. Corrosives can also damage or even destroy metal.
How do you identify a physical property?
A physical property is a characteristic of a substance that can be observed or measured without changing the identity of the substance. Physical properties include colour, density, hardness, and melting and boiling points.
How do you identify a chemical change?
A chemical change always produces one or more types of matter that differ from the matter present before the change.
What changes to atom happen when there is a physical change
No change in the bonding between atoms
What changes in atoms happen when a chemical change occurs?
The atom bond breaks and involves the rearrangement of atoms?
What does a chemical reaction do?
Involves energy being taken in and given out
Is a physical or chemical change easier to change?
A physical change is much easier to reverse than a chemical change
Where do atoms go in a chemical change?
In a chemical reaction, atoms and mass are conserved throughout.
How to structure a chemical reaction?
Reactants are the materials that we begin with, these are on the LHS of the worded equation. Products are created as a result of the reactants reacting together. These are on the RHS of the worded equation.
The arrow in a worded equation means?
reacts to produce
What does it mean when a word is written above the arrow?
it is a catalyst or not a substance
What state does ‘s’ symbolise?
Solid
What state does ‘l’ symbolise?
liquid
What state does ‘aq’ symbolise?
solution
What state does ‘g’ symbolise?
gas
Signs of a chemical change could be (2)?
A colour change; gas given off, new odour formed, a new substance appearing (precipitate), a substance disappearing, a change in temperature, light or sound produced
Define flammability
Flammability is the ability of a substance to ignite (have a flame) and to continue burning
Define corrosion
Corrosion is a chemical reaction where a metal reacts with oxygen; it usually involves water.
The worded equation for the formation of rust is?
iron + water + oxygen -> rust (or iron oxide)
Effects of corrosion?
Corrosion limits the use of metals for some purposes. e.g. ships, bridges or buildings
Methods to counter corrosion?
coatings, paint, grease and other metals.
