This question is about properties of materials.
High-performance orthopedic implants can be made from stainless steel or carbon-fiber reinforced polyether ether ketone (CF-PEEK).
The table shows some information about stainless steel and CF-PEEK.
| Stainless steel | CF-PEEK | |
|---|---|---|
| Density (g/cm3\text{g/cm}^3g/cm3) | 8.008.008.00 | 1.451.451.45 |
| Relative strength | 111 | 333 |
| Biocompatibility | low | high |
| Resistance to corrosion | moderate | high |
Describe and explain two reasons why high-performance orthopedic implants are made from CF-PEEK instead of stainless steel.
Look at the structure of Kevlar: [−CO−C6H4−CO−NH−C6H4−NH−]n\left[ -\text{CO}-\text{C}_6\text{H}_4-\text{CO}-\text{NH}-\text{C}_6\text{H}_4-\text{NH}- \right]_n[−CO−C6H4−CO−NH−C6H4−NH−]n What type of molecule is Kevlar?
Nanoparticles of zinc oxide are being used to make antimicrobial coatings for orthopedic implants.
A zinc oxide nanoparticle has a diameter of 43 nm43\text{ nm}43 nm. The diameter of a zinc atom is 0.18 nm0.18\text{ nm}0.18 nm.
Estimate how many times larger the zinc oxide nanoparticle is, compared to a zinc atom. Give your answer to 1 significant figure.
Zinc oxide is used as an antibacterial agent. Suggest why 1 g1\text{ g}1 g of zinc oxide is more effective when used as nanoparticles rather than as a bulk powder.