Definitions

• What is diffusion?

  The process in which particles mix by colliding randomly with each other
• What characterizes a mixture?

  A mixture contains two or more substances that are not chemically combined
• What is a solution?

  A mixture obtained when a solute is dissolved in a solvent
• What does soluble mean?

  Will dissolve in a solvent
• What is a solute?

  The substance you dissolve in a solvent to make a solution
• What is a solvent?

  The liquid in which a solute is dissolved to make a solution
• What is the nucleon number?

  The total number of protons and neutrons in an atom
• What are isotopes?

  Atoms of the same element with different numbers of neutrons
• What are radioisotopes?

  Unstable atoms that break down, giving out radiation
• What are elements?

  Substances that contain only one type of atom
• What is a compound?

  A substance made of atoms of different elements bonded together
• What is an ion?

  A charged particle with an unequal number of protons and electrons
• What is an ionic bond?

  A bond that forms between ions of opposite charges
• How do metals and non-metals behave in ionic bonding?

  Metals lose electrons, non-metals gain electrons
• What are covalent bonds?

  A chemical bond formed when two atoms share electrons
• What is relative atomic mass (Ar)?

  The average mass of its isotopes compared to an atom of carbon-12
• What is a metallic bond?

  The attraction between metal ions and free electrons
• What is valency?

  The number of electrons an atom loses, gains, or shares to form a compound
• What is relative formula mass (Mr)?

  The mass of one formula unit of an ionic compound
• What is relative molecular mass (Mr)?

  The mass of a molecule
• What is a mole?

  The amount that contains the same number of units as the number of carbon atoms in 12 grams of carbon-12
• What is an empirical formula?

  Shows the simplest ratio in which the atoms in a compound are combined
• What is a molecular formula?

  Gives the actual number of each different atom present in a molecule
• What is the concentration of a solution?

  The amount of solute, in grams or moles, that is dissolved in 1 dm³ of solution
• What is oxidation?

  The gain of oxygen and loss of electrons
• What is reduction?

  The loss of oxygen and gain of electrons
• What is an ionic equation?

  Shows the ions that take place in a reaction
• What is a redox reaction?

  Any reaction in which electrons are transferred, one substance is oxidized and the other is reduced
• What are conductors?

  A substance that allows heat or electricity to pass through it easily
• What are insulators?

  A poor conductor of heat or electricity
• What are electrodes?

  The conductors used to carry current into and out of an electrolyte
• What is electrolysis?

  The process of breaking down a compound by passing a current through it
• What is an electrolyte?

  The liquid through which the current is passed
• What is electroplating?

  Using electricity to coat one metal with another
• What are exothermic reactions?

  Reactions that give out energy, causing temperature to rise
• What are endothermic reactions?

  Reactions that take in energy from their surroundings
• What is a fuel?

  Any substance we can use to provide energy
• What is a reversible reaction?

  A reaction that is endothermic in one direction and exothermic in the other
• What is the rate of reaction?

  How many successful collisions there are in a given unit of time
• What are catalysts?

  A substance that speeds up the rate of reaction but remains chemically unchanged