Answer:
= 72900 years
Explanation:
- The half-life is the time taken by a radioactive material to decay by half the original amount.
- The half-life of plutonium-239 is 24300 years which means it takes 24300 years to decay by half the original amount.
To calculate the time taken for a mass of 8 kg to decay to 1 kg we use;
New mass = Original mass x (1/2) ^n, where n is the number of half-lives
Therefore;
1 kg = 8 kg × (1/2)^n
1/8 = (1/2)^n
solving for n;
n =3
Therefore;
Time = 3 × 24300 years
= 72900 years
It will, therefore, take 72900 years for 8 kg of plutonium-239 to decay to 1 kg.
Explanation:
i think its B but i'm not fully sure (Correct)
Nanochemicals can be defined as chemicals generated by using nanomaterials (materials that possess of size on nanometer dimensions). The nanochemicals are used in multiple different applications including chemical warfare, bicycle making, armor design and military weapons crafting. The most commonly used and observed nanochemicals are carbon nanotubes that are used a ton in industry for applications such as stronger materials (stronger bicycles).
Smart materials are exquisitely designed materials whose property(ies) can be modified with the use of an external stimulus such as temperature, stress, pH, and so on. Some examples of smart materials include shape memory materials, piezoelectric materials, ferrofluids, self-healing materials, and such. Applications involve memory pillows, memory based solar panels (for satellites), light sensitive glasses, and so on.
Specialized materials are made specifically to perform a specified task or function. Applications involve electronic equipment (high purity silicon & germanium), machine tools (high tungsten high carbon steel), dental filling (dental amalgam), and so on.
Answer:
1.59 x 10⁻²⁵ J.
Explanation:
- The energy of a photon is calculated Planck - Einstein's equation:
E = h ν
, where
E is the energy of the photon,
h is Planck's constant <em>(h = 6.626 x 10
⁻³⁴ J.s)</em>
ν is the frequency of the photon
-
There is a relation between the frequency (ν
) and wave length (λ).
λ.ν = c,
where c is the speed of light in vacuum (c = 3
.0 x 10
⁸ m/s).
λ = 125 cm = 1.25 m.
<em>Now, E = h.c/λ.</em>
∴ E = h.c/λ = (6.626 x 10
⁻³⁴ J.s) (3
.0 x 10
⁸ m/s) / (1.25 m) = 1.59 x 10⁻²⁵ J.
