Download Summing up 17. endothermic exothermic reaction reactants energy

Chapter 4: Chemical energy
Summing up
Science Quest 3: Glossary pages 254–61
Student: ........................................................................................................................................................ Class: . ...........................................................................
Complete the statements below to compile a summary of this unit. The missing words can be found
in the word list below.
  1. Chemical reactions which absorb energy from the surroundings and lower the temperature are
called endothermic reactions.
  2. Reactions which increase the temperature of the surroundings are called exothermic
reactions.
  3. Stored chemical energy is transformed into other forms of energy when a chemical
reaction
takes place.
  4. Whether energy is released or absorbed during a chemical reaction can be observed by
reactants
comparing the temperature of the
before the reaction with the temperature
of the products after the reaction.
energy
  5. Explosions are chemical reactions in which a large amount of
is released very
quickly.
  6. When an atom loses an electron, it forms a
positive
ions
  7. Salt solutions conduct electricity well because
through the solution.
  8. A solution that conducts electricity is called an
ion.
electrolyte
are able to carry the current
.
electrons
  9. Metals are good conductors of electricity because free
towards the positive terminal of a battery.
cells
10. A battery consists of several
connected together.
11. Chemical reactions in a cell cause electrons to flow from the
through the device being powered, and back to the cell.
fossil
fuels
12. Coal, natural gas and oil are
can move freely
negative
electrode
.
13. Crude oil is a mixture of many hydrocarbons .
14. An increase in the amount of greenhouse gases is largely responsible for global warming.
biofuels
15. Fuels that consist of plant and animal wastes are called
.
biogas
16. Plant and animal wastes can be converted to
in a digester. The residue can
fertiliser
be used as
.
17.
Alcohol
produced from fermented sugar or corn is a biofuel that can be used to fuel
motor vehicles.
biofuels
fossil
alcohol
electrolyte
electrons
negative
ions
fertiliser
biogas
greenhouse
reactants
hydrocarbons
reaction
positive
cells
endothermic
exothermic
fuels
energy
© John Wiley & Sons Australia, Ltd 2009
Science Quest 3 Student Workbook 43