Hello 黎sir, i have 2 question want to ask

1)electrons can move from conductor to another conductor, can positive charges also move like that?

=> Yes. But in HKCEE syllabus, the only charges moving in conductors is electrons which are negatively charged.

For example: Sodium chloride solutions: Na+ and H+ will move to the negative electrode.

2)what is the meaning of sharing electrons?

=> Yes. Sharing of electrons mean:

If two conductors are in contact, the charges will share among the surface make the "Potential" of the surface are the same.

In HKALE syllabus, we call this "Equipotential Surface"! But this is not included in HKCEE syllabus.

Friction / Air Friction is a force to oppose the motion.

你好黎sir

我是一名中三學生,

I'd like to know what is friction and air resistance.

你好黎sir

我是一名中三學生

deductive geometry一課學極都唔好

上網搵notes發現左你呢個網

想知Deductive Geometry 演繹幾何 (中英對照)

你入面d question有冇答案呢?

煩請回答 謝謝

state one assumption in 計算 lantent heat of vaporization

答案: constant rate of energy loss to surroundings

do not accept energy loss to surroundings<<<<點解呢??

thx~