Radioactivity

Half-life

the time that it takes for half of the radioactive atoms to become stable

Fission

the splitting a nucleus into smaller fragments, with release of large amount of energy

Fusion

the combining nuclei to produce a nucleus of greater mass

Nuclear Reactor

the device used to initiate and control a self-sustained nuclear chain reaction

Calorimeter

the apparatus for measuring heat from a chemical reaction

Thermochemical Reaction

the chemical equation that includes the enthalpy change, ΔH

Specific Heat

the amount of heat needed to raise 1 g of substance 1 oC

Joule

the SI unit of energy

Beta decay

a radioactive process where an unstable nucleus emits a beta particle (high speed electron) and the atom changes from one element to another

Heat

the flow of energy from an object of higher temperature to one of lower temperature

Endothermic

2 AlCl3 (aq) + 3 H2 (g) -- > 2 Al (s) + 6 HCl (aq) ΔH = 1049 kJ

Exothermic

the beaker gets hot

Exothermic

CH4 (g) + 2 O2 (g) -- > CO2 (g) + 2 H2O (g) + 890 kJ

Endothermic

absorbs heat

Endothermic

reactants below, products high

Endothermic

Photosynthesis

True

Heat flows from warmer object to cooler one

True

Radioactivity is greatly affected by temperature, pressure and catakysts