Date | May 2019 | Marks available | 2 | Reference code | 19M.3.sl.TZ1.6 |
Level | SL | Paper | 3 | Time zone | TZ1 |
Command term | Describe | Question number | 6 | Adapted from | N/A |
Question
Nanotechnology has allowed the manipulation of materials on the atomic level.
Describe the structure and bonding of a carbon nanotube.
Structure:
Bonding:
Suggest one application for carbon nanotubes.
Markscheme
Structure:
giant covalent/network covalent [✔]
Note: Accept “cylindrical/tube shaped”.
Bonding:
each carbon covalently bonded to 3 other carbons
OR
each bond has order of 1.5
Note: Accept “has delocalized electrons” OR “has sp2 hybridization”.
Any one of:
3D electrodes [✔]
catalysts [✔]
biosensors [✔]
molecular stents [✔]
body armour [✔]
synthetic muscles [✔]
micro transistors/circuitry/capacitors/electrodes [✔]
reinforcing phase in a matrix/composite material «such as concrete» [✔]
micro antenna [✔]
stealth technology [✔]
water/air filtration [✔]
solar cells [✔]
tennis racquets [✔]
microelectronic circuits [✔]
Note: Do not accept just general answerssuch as “medicine” or “defence”.
Examiners report
Most students were aware that nanotubes have a tubular structure, but answers to the bonding were rarely detailed enough to gain the second mark.
Only a few students gained this mark and they usually gave the use of nanotubes for a reinforcing.