<u>Answer:</u> The edge length of the unit cell is 0.461 nm
<u>Explanation:</u>
We are given:
Atomic radius of iridium = 0.163 nm
To calculate the edge length, we use the relation between the radius and edge length for FCC lattice:

Putting values in above equation, we get:

Hence, the edge length of the unit cell is 0.461 nm
Explanation:
is used for making ropes, used for climbing rocks and for making parachutes. Their usage shows that nylon fibres have high tensile strength
Answer:
See the answer below
Explanation:
<em>The duration of flushing the eyes at the eyewash station in case of accidental contact with chemicals depends of the nature of the chemical.</em>
If the chemical is known to be a <u>non-irritant or mild-irritant</u> one, a <u>5-minute </u>washing time is recommended as the first aid. before seeking the help of a physician,
For <u>moderate to severe irritant</u> chemicals, an immediate <u>15-20 minutes</u> washing period is recommended before seeking further medical help.
For <u>corrosive and strong alkalis</u> chemicals, <u>30 and 60 minutes</u> washing are recommended respectively before seeking the attention of a physician.
However, if the nature of the chemical is unknown,<u> a minimum of 20-minutes washing is generally recommended</u> as first aid before seeking immediate medical help.