0714 820 596 Channa Asela Teacher, S ... - Part1.pdf · 0714 820 596 Channa Asela Teacher, S. Thomas’ College, Mt. Lavinia P a g e 2 4) Therefore there are ……. electrons in

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Types of materials

1) …………………….

2) …………………….

3) Semiconductors

Conductors

1) …………….. have free …………………………. which can flow freely.

2) Therefore ………………….. can conduct ………………..

3) ………………. have less ……………

eg. – Copper, Aluminium, iron (…………..)

Insulators

1) The ………………… of …………… are being used to make ……………. bonds.

2) Therefore, ……………… do not have free ………………….

3) Hence ……………… cannot conduct …………….

4) ……………… have high ………….

eg – Ebonite, …………., …………, dry wood, asbestos, glass

Semiconductors

1) …………………… conduct a small amount of ……………...

2) Therefore the …………………. of …………… are more than the ……………. of the ……………..

but less than the ………………… of ……………..

3) These ………………….. belong to group …………...

eg – …………. (Silicon), ……… (Germanium)

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4) Therefore there are ……. electrons in the ……….. energy level of ……….. or ………

5) Therefore there are ………. valence electrons in ………. or ………. atoms.

6) These ……… valence electrons of a …….. or ……… atom will be shared with the valence

electrons of another 4 …………. or ………… atoms respectively and form 4 …………… bonds.

7) Therefore there are no free …………. in an ………… atomic lattice at ……….. (………….)

8) These …………. bonds are very …………. bonds.

9) Some of these …………….. bonds will break when the ………..…. increases.

10) Therefore there will be free …………..

11) The place where these …………. were present earlier will now become …………..

12) These …………… places are called ‘…………….’.




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13) ‘…………..’ can attract an ………… charged ……………. from an adjacent …………….

14) Therefore ‘…………….’ are ……………. charged.

15) After attracting a ………….. charged ………….. into the …………… charged ‘………..’, the

‘…………….’ will disappear.

16) The place from where the ……………. charged ……… came, will now become a

………………… charged ‘…………..’.

17) Therefore the ……………… charged …………….. move in one ………. and the …………

charged ‘…………..’ move in the opposite …………...

18) When an electrical potential difference is applied across a …………, the ………………

charged ‘………….’ move from the …………… to the …………. potential.

19) When an electrical potential difference is applied across a …………………., the …………..

charged …………….. move from the ……………… to the ……………… potential.




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20) In metallic ……………, the ………….. charged ………………. are the only charged …………

that conduct …………...

21) But in …………….., the ………….. charged ………… and the ………….. charged ‘………..’

conduct ……………...

22) Therefore ……………….. have ………….. types of …………….

23) ……………. charged ‘…………..’ are formed by removing a …………. charged …………...

24) Therefore, the number of ……………. charged ‘………….’ are equal to the number of

……………. charged ………………… in pure …………….




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Intrinsic semiconductors

1) …………….. semiconductors such as……….. and ……….. without ……….. (doping)

………….. are called intrinsic semiconductors.

2) Number of …………… charged ‘………..’ and ……………… charge free ………….. are

…………….. in ……………… semiconductors

Extrinsic semiconductors

1) When ………… semiconductors such as …………. or ………. are ……… (doped) with a

minute amount of Group ………. - …… or …… or ……… (gallium) or …….. (Indium)

or Group ……… - …… or ……….. (Arsenic) or ……….. (Antimony) are called …………

semiconductors.

2) In ………….. semiconductors, the number of …………. charged ‘………..’ and ………….

charged free ……………… are not ………….

p-type semiconductors

1) p-type semiconductors are made by mixing a minute amount of group ……….. –

…… or ……… or ………. or ……….. with ………… semiconductors such as Group ……… -

………. or ……….

2) Since …., ……., …….. and ……….. belong to group …………, their last energy level

contains only …………… electrons.

3) Therefore when a minute amount of group ………. - ……… or …….. or ……… or ……….

are added to group …….. – …….. or ………, there will be a ‘…………’ without an ……….

4) ‘……….’ conduct electricity as ……….. charges.

5) Therefore the conductivity of ……… or ……….. will ………...

6) By …………… (doping) a minute amount of Group ………… – ……… or ……. or ……. or

………, the ……….. charged ……….. will ………...




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7) Therefore the …………… semiconductor is now called ……….. type (…….-type)

semiconductor.

8) Since ‘……………..’ can accept …………., the group ……….. atoms are called

‘……………….’.




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n-type semiconductors

1) n-type semiconductors are made by …………. (doping) a minute amount of group

………. – ……. or ……… or ………. with ………. semiconductors such as Group …… - ……

or ………..

2) Since ……., ……, ………. belong to group ………, their last energy level contains …….

electrons.

3) Therefore when a minute amount of group ………. - …… or ……… or ………. are

added to group ……….. – ……….. or ……….., there will be a free ‘…………….’

4) Therefore the conductivity of ………. or …………will ………….

5) By ………… (doping) a minute amount of Group …….. – …… or ……… or ……., the

……………….. charged free ………. will ………….




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6) Therefore the ……….. semiconductor is now called ……………… type (……..-type)

semiconductor.

7) Since free ……….. were …………. by group ……… atoms, the group ……….. atoms are

called ‘……………..’.




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0714 820 596 Channa Asela Teacher, S ... - Part1.pdf · 0714 820 596 Channa Asela Teacher, S. Thomas’ College, Mt. Lavinia P a g e 2 4) Therefore there are ……. electrons in