Iridium-192 is used in cancer treatment, a small cylindrical piece of 192 Ir, 0.6 mm in diameter (0.3mm radius) and 3.5 mm long, is surgically inserted into the tumor. if the density of iridium is 22.42 g/cm3, how many iridium atoms are present in the sample?
Let us start by computing for the volume of the cylinder. V = π(r^2)*h where r and h are the radius and height of the cylinder, respectively. Let's convert all given dimensions to cm first. Radius = 0.03 cm, height is 0.35cm long.
V = π * (0.03cm)^2 * 0.35 cm = 9.896*10^-4 cm^3
Now we have the volume of 192-Ir, let's use the density provided to get it's mass, and once we have the mass let's use the molar mass to get the amount of moles. After getting the amount of moles, we use Avogadro's number to convert moles into number of atoms. See the calculation below and see if all units "cancel":
9.896*10^-4 cm^3 * (22.42 g/cm3) * (1 mole / 191.963 g) * (6.022x10^23 atoms /mole)
= 6.96 x 10^19 atoms of Ir-122 are present.
The answer is large leaves.
These enable the plant to absorb more of the scarce sunlight it receives, so it can create enough nutrients for it to survive.
Answer:
Protons have a much larger volume than neutrons.
There are some methods that differentiate waves; one thing is by its medium.
Electromagnetic waves did not require a medium for transmission such as in a
vacuum while mechanical waves require a medium to travel such as air, water or
anything that can serve as a transmission aid.
The most common sample of EM waves in
telecommunication is radio,
light and infra-red signals. An example of a mechanical wave is a sound
wave, which requires air to travel. Oscillating molecules made the
sound waves.
