Chemistry question!!!!!

Yat Hei just cannot answer either of questions. he can't explain the origin of electrical conductivity, nor energy source for ionization of atoms.

1.
you're right, every element has electrons. however, one atom is very very small.
wen we're talking about a material or a lump of element, there's a lot of atoms.

for electricity to be conducted, electrons must be able to go from one atom to another.
for metals like iron, aluminium and copper, atoms are closely-packed. electrons of atoms can "delocalize", escape from the nucleus and go to another atom nearby. the "sea of electrons" allows electrons to freely travel, conducting electricity.

for non-metals like oxygen, sulphur and carbon (in form of diamond), either the atoms are too far away from each other, or the electrons cannot escape easily to form sea of electrons. therefore under normal circumstances, they cannot conduct electricity.

(carbon in form of graphite 石墨 can, however, conduct electrons due to its special structure and arrangement of atoms. it can be found in pencil lead 鉛筆芯.)


2.
usually, the reaction is started by some energy input, in form of heat, light, fire/spark. once the reaction has been started, energy is continuously given out.
for example, sodium burns in air to give sodium oxide. a flame is used to provide energy; after reaction has started, it burns vigorously, continuously give out heat, light, flame and hence energy. even the initial flame is removed, the burning can self-sustain. the reaction will go on itself.

some of the element can't conduct eletron because it doesn't have moblie eletron

如果你所講既element 係metal,
咁佢咪會conduct electricity.

a atom change into a ion by losing or gaining electrons
metal by losing electrons to form ion
non-metal by gaining electrons to form ion

吾知解吾解答到你既問題呢?