CAIE Chemistry IGCSE

Flashcards for CAIE Chemistry IGCSE topics

What is Diffusion?

The net movement of particles from an area of high concentration to an area of low concentration.

What is a Gas?

The state of matter where the particles have the most energy, are relatively spread out, and move randomly in all directions.

What is Kinetic particle theory?

The theory that models the three states of matter by representing the particles as small solid spheres to explain melting, boiling, freezing, condensing and sublimation.

What is a Liquid?

The state of matter where the particles are arranged randomly and close together, able to move past each other.

What is Relative molecular mass?

The mass of one molecule, relative to the mass of one carbon-12 atom, calculated by the sum of the atomic masses of all the atoms in the molecule.

What is a Solid?

The state of matter where the particles hold a regular arrangement, have the least amount of energy, and vibrate in fixed positions.

What is Sublimation?

The process of a solid turning straight into a gas, without first becoming a liquid.

What is the distinguishing property of a solid?

Particles are closely packed and have a fixed arrangement.

What is the distinguishing property of a liquid?

Particles are close together but have a random arrangement.

What is the distinguishing property of a gas?

Particles are spread apart and have a random arrangement.

Describe the structure of solids in terms of particle separation, arrangement and motion.

Particles hold a regular arrangement and have the least amount of energy, vibrating in fixed positions and cannot be compressed.

Describe the structure of liquids in terms of particle separation, arrangement and motion.

Particles are arranged randomly and close together, able to move past each other and take the shape of their container, and cannot be compressed.

Describe the structure of gases in terms of particle separation, arrangement and motion.

Particles are arranged randomly and have the most energy, being relatively spread out and move randomly in all directions and can be compressed.

What is melting?

Solid to liquid.

What is boiling?

Liquid to gas, where bubbles of gas will form throughout the liquid, rising to the surface to evaporate into the surroundings.

What is evaporation?

Liquid to gas, where the particles of gas formed will escape from the surface of the liquid only.

What is Freezing?

Liquid to solid.

What is Condensation?

Gas to liquid.

Explain changes of state in terms of kinetic particle theory for melting, boiling and evaporation.

Heat is transferred into kinetic energy in the particles, so they gain enough energy to overcome the intermolecular forces.

Explain changes of state in terms of kinetic particle theory for freezing and condensing

Energy is lost from the particles in the substance. Intermolecular forces are formed between the particles, holding the particles closer together

Explain in terms of kinetic particle theory, the effects of temperature increases on the volume of a gas.

Increasing the temperature increases the kinetic energy of the gas particles, so the gas particles move and collide with the container more quickly, spreading further apart.

Explain in terms of kinetic particle theory, the effects of pressure changes on the volume of a gas.

Increasing the pressure decreases the volume of the gas, as the gas particles are forced closer together. Decreasing the pressure increases the volume of the gas, as the gas particles can spread further apart.

Explain the effect of relative molecular mass on the rate of diffusion of gases.

The larger the relative molecular mass, the slower the diffusion rate of the gas because the heavier the particles, the slower they move.

What is an Anion?

A negatively charged ion, formed when a nonmetal atom has gained an electron

What is an Atom?

The smallest part of an element that can exist. All substances are made up of atoms. Atoms contain a positively charged nucleus surrounded by negatively charged electrons.

What is an Atomic nucleus?

Positively charged object composed of protons and neutrons at the centre of every atom with one or more electrons orbiting it.

What is an Atomic number (proton number)?

The number of protons in the nucleus of an atom.

What is a Cation?

A positively charged ion, formed when a metal atom has lost an electron.

What is a Compound?

A substance made up of two or more types of atoms chemically combined together.

What is a Covalent bond?

A strong bond formed when a pair of electrons is shared between two (nonmetal) atoms.

What is Diamond?

A giant covalent structure which is made up of carbon atoms each of which form four covalent bonds with four other carbon atoms.

What does ductile mean?

Can be bent or hammered into other shapes due to its pliability and flexibility.

What is an Electron?

Negatively charged subatomic particle which orbit the nucleus at various energy levels.

What is an Electron shell?

Different energy levels in atoms, occupied by electrons.

What is an Element?

A substance made up of only one type of atom.

What is Graphite?

A giant covalent structure which is made up of carbon atoms each of which form three covalent bonds with three other carbon atoms.

What is an Ion?

An atom or molecule with an electric charge due to the loss or gain of electrons.

What is an Ionic bond?

A strong electrostatic attraction between oppositely charged ions.

What is an Ionic compound?

Chemical compound formed of ions, held together by strong electrostatic forces.

What are Isotopes?

Different atoms of the same element that have the same number of protons but different numbers of neutrons.

What is a Lattice?

A repeating regular arrangement of atoms/ions/molecules.

What are Macromolecules (giant covalent structure)?

A molecular structure containing many atoms covalently bonded together.

What does malleable mean?

Capable of being deformed and moulded into various shapes.

What is Mass number (nucleon number)?

The total number of protons and neutrons in the nucleus of an atom

What is Metallic bonding?

The electrostatic attraction between the positive ions in a giant metallic lattice and a ‘sea’ of delocalised electrons

What are Metals?

Elements that react to form positive ions.

What is a Mixture?

A substance made up of two or more elements or compounds, but are not chemically bonded together.

What is a Neutron?

Neutral subatomic particle present in the nucleus of the atom.

What are Noble gases?

The elements in Group 0 of the periodic table.

What are Non-metals?

Elements that react to form negative ions.

What is Nucleon number (mass number)?

The total number of protons and neutrons in the nucleus of an atom.

What is a Proton?

Positively charged subatomic particle present in the nucleus of the atom.

What is Proton number (atomic number)?

The number of protons in the nucleus of an atom.

What is an element?

a substance made from only one type of atom.

What are elements?

pure substances that cannot be broken down further

What is a compound?

a substance made from two or more elements that have reacted with each other and formed chemical bonds between atoms

What is a mixture?

a substance made up of two or more elements or compounds, but are not chemically bonded together

What does the term Electronic configuration mean?

the arrangement of the electrons in each electron shell in an atom

What are isotopes?

different atoms of the same element that have the same number of protons and electrons but different number of neutrons

What is an ion?

An atom or molecule with an electrical charge, due to the loss or gain of an electron

What results from the gain of an electron to a non-metal?

a negative charged ion, known as an anion

What results from the loss of an electron from a metal?

a positively charged ion, known as a cation.

What is an ionic bond?

a strong electrostatic attraction between the oppositely charged ions

Describe the formation of ionic bonds between ions of metallic and non-metallic elements

Metals lose electrons to form positively charged cations, while non-metals gain electrons to form negatively charged anions

What is a covalent bond?

formed when a pair of electrons are shared between two atoms (two non-metals)

What are metallic bonds?

the electrostatic attraction between the positive metal ions (cations) in a giant metallic lattice and a ‘sea’ of delocalised electrons

What is Avogadro’s constant?

The number of atoms, molecules or ions in a mole of a given substance, 6.02x1023

What is Concentration?

The amount of solute dissolved in a volume of a solution, measured in g/dm3 or mol/dm3

What is Empirical formula?

The simplest whole number ratio of atoms of each element in a compound.

What is Limiting reactant?

The reactant that is completely used up since it limits the amount of products formed.

What is Molar volume?

The volume occupied by one mole of gaseous molecules.

What is Molar volume at RTP?

The volume occupied by one mole of molecules of any gas at room temperature and pressure (RTP)

What is a Mole?

The unit for amount of substance.

What is Molecular formula?

The actual ratio of atoms of each element present in a compound.

What is Percentage purity?

The percentage ratio of the mass of a pure compound in an impure sample.

What is Percentage yield?

The percentage ratio of the actual yield of product from a reaction compared with the theoretical yield.

What is Relative atomic mass, Ar?

The average mass of an element, Ar , as the average mass of the isotopes of an element compared to 1/12th of the mass of an atom of carbon-12.

What is Relative formula mass, Mr?

The sum of the relative atomic masses in an ionic compound.

What is Relative molecular mass, Mr?

The sum of the relative atomic masses in a molecule.

What are Spectator ions?

Ions that are present on both sides of an equations so remain unchanged and can be cancelled out to leave the ionic equation

What are Anhydrous substances?

Anhydrous substances do not have water molecules in its structure

What are Biological catalyst (enzymes)?

Biological catalysts increase the rate of biological reactions, common biological catalysts are enzymes.

What is a Catalyst?

A catalyst increases the rate of a reaction and is unchanged (not used up) at the end of a reaction

What is a Chemical change?

Requires a chemical reaction and the products must have a different chemical composition to the reactants.

What is Collision theory?

Describes how reactant particles, with sufficient activation energy Ea must collide with each other successfully for a chemical reaction to occur.

What is a Physical change?

Requires energy and involves a change in state. The form of the chemical is changed but the chemical composition remains the same.

What is Rate of reaction?

The measure of the amount of product formed or reactant used over time.

What is a Redox reaction?

A reaction in which both oxidation and reduction occur simultaneously.

What is Reduction?

A reaction involving the loss of oxygen. Reduction is the gain of electrons, decreasing its oxidation number

What is a Reversible reaction?

A reaction in which the products can react together to reform the reactants.

What is an Anode?

The positive electrode. It is where negatively charged ions lose electrons in oxidation reactions.

What is a Cathode?

The negative electrode. It is where positively charged ions gain electrons in reduction reactions.

What is a Chemical cell?

A cell which converts chemical energy to electrical energy.

What is an Electrode?

A solid conductive material through which electricity can flow.

What is Electrolysis?

The decomposition of an ionic compound (molten or aqueous) using electricity.

What is an Electrolyte?

A solution containing free ions from a molten or aqueous ionic substance.

What is Electroplating?

The process of coating a metal with a thin layer of another metal by electrolysis to improve the metal's corrosion resistance or to improve the metal’s appearance.

What is a Fuel cell?

An electrochemical cell which continuously produces a voltage when supplied with a fuel and oxygen.

What is a Hydrogen-oxygen fuel cell?

A fuel cell in which hydrogen and oxygen are the reactants used to produce a voltage. Water is the only product.

What does inert mean?

Unreactive.