Chemistry Revision Flashcards Preview

Chemistry S4 keywords and defenitions > Chemistry Revision > Flashcards

Flashcards in Chemistry Revision Deck (44):

Define acid

An acid is a substance that can attack metal clothing or the skin. Has a PH of less than 7. They are proton (H+ ion) donators.


Give me the definition of activation energy

Activation energy is the minimum energy needed to start a reaction.


Explain Alkali metals

An alkali metal is elements in group 1 of the period table.


Give me an example of an alkali metal.

An example is Lithium (Li). Sodium (Na). Potassium (K)


Define Alkane

An alkene is a saturated hydrocarbon that has no double bonds between the carbon atoms


Give me an example of an alkane.

An example of an alkane is Ethane


What does alkene mean?

An alkene is unsaturated hydrocarbon that contains a carbon bond.


Explain what alloy means.

An alloy is a mixture of metals (and sometimes non- metals)


Give me an example of an alloy

An example is Brass- a mixture of Copper and Zinc.


Define Aluminium

Aluminium is a low density corrosion- resistant materials used in many alloys.


Explain Anhydrous

Anhydrous describes a substance that does not contain water.


What does an aqueous solution mean?

An aqueous solution is a mixture made by adding a soluble substance to water.


Define atoms.

Atoms are the smallest part of an element which can be recognised as an element.


Explain atomic number.

Atomic number is the number of protons (which equals the number of electrons) in an atom. It is sometimes called the proton.


What does atomic weight mean?

Atomic weight is the historical term that was used before relative atomic masses were defined in the 20th century.


Define a base.

A base is an oxide, hydroxide or carbonate of a metal that forms a salt as a product when it reacts with acid. They are proton (H+ion) acceptors.


Explain biodegradable.

Biodegradable is materials that cane broken down by microorganisms.


What does biodiesel mean?

Biodiesel is fuel for cars made from plant oils.


Define Biofuel

Biofuel is fuel made from animal or plant products.


Give me the meaning of bioleaching

Bioleaching is the process of extraction of metals from ores using microorganisms.


Define a blast furnace

A blast furnace is the huge reaction vessels used in industry to extract iron from its ore.


What does bond energy mean?

Bond energy is the energy needed to break a particular chemical bond.


Define a Burette

A burette is a long glass tube with a tap at one end makings to show volumes of liquid used to add precisely known amounts of solution to a solution in a conical flask below it.


Explain Calcium Carbonate

Calcium Carbonate is the main compound found in limestone. It is white solid whose formula is CaCO


What does Calcium Hydroxide mean?

Calcium Hydroxide is a white solid made by reacting calcium oxide with water. It is used as a cheap alkali in industry.


Define Calcium Oxide

Calcium Oxide is a white solid made by heating limestone strongly. For example in a lime kiln.


Explain Carbon Monoxide

Carbon Monoxide is a toxic gas whose formula is CO


What does cast iron mean?

Cast Iron is an impure iron taken directly from a blast furnace.


Define a Catalyst

A catalyst is a substance that increases the rate of a chemical reaction. It is not used or changed in the reaction.


Explain what cement means

Cement is a building material made by heating limestone and clay.


Define Chromatography

Chromatography is the process whereby small amounts of dissolved substances are separated by running a solvent along a material such as absorbent paper.


What does Collision theory mean?

Collision theory is an explanation of chemical reactions that says particles colliding have to have a sufficient amount of energy in order for a reaction to take place.


Define a compound

A compound is a substance made when two or more elements are chemically bonded together. For example water (H20) is a compound made from hydrogen and oxygen.


Explain what Concrete means

Concrete is a building material made by mixing cement sand and aggregate (crushed rock) with water.


Define convection currents

Conviction currents are the circular motion of matter caused by heating in fluids.


Explain a copper- Rich core

A copper Rich- core is a rock that contains a high proportion of a copper compound.


Define Core

The core is the centre of the earth


Give me the meaning of Covalent Bonding

Covalent bonding is the attraction between two atoms that share one or more pairs of electrons.


Define Cracking

Cracking is the reaction used in oil industry to break down large hydrocarbons into smaller more useful ones. This occurs when the hydrocarbon vapour is either passed over a hot catalyst or mixed with steam and heated to a high temperature.


What does crust mean?

The crust is the outer solid layer of the Earth.


Define Delocalised Electron

Delocalised Electrons is a bonding electron that is no longer associated with any one particular atom.


Explain displace

Displace means when one element takes place of another in a compound.


Give me the meaning of distillation

Distillation is the separation of a liquid from a mixture by evaporation followed by condensation.


Define Dot and Cross Diagram

Dot and Cross diagrams are a drawing to show the arrangement of the outer shell electrons only of the atoms or ions in a substance.