Answer:
v = 7.3 × 10⁶ m/s
Explanation:
Given data:
Velocity of electron = ?
Wavelength = 100 pm
Solution:
Formula:
λ = h/mv
λ = wavelength
h = planck's constant
m = mass
v = velocity
Now we will put the values in formula.
100 ×10⁻¹² m = 6.63 × 10⁻³⁴ j.s / 9.109 × 10⁻³¹ kg × v
v = 6.63 × 10⁻³⁴ kg.m²/s / 9.109 × 10⁻³¹ kg ×100 ×10⁻¹² m
v = 6.63 × 10⁻³⁴ m/s /910.9 × 10⁻⁴³
v = 0.0073 × 10⁹ m/s
v = 7.3 × 10⁶ m/s
Answer
7665 years
Procedure
Let N₀ be the amount of carbon-14 present in a living organism. According to the radioactive decay law, the number of carbon-14 atoms, N, left in a dead tissue sample after a certain time, t, is given by the exponential equation:
N = N₀e^(-λt)
where λ is the decay constant which is related to half-life (T1/2) by the equation:

Here, ln(2) is the natural logarithm of 2.
The percent of carbon-14 remaining after time t is given by N/N₀.
Using the first equation, we can determine λt.
The half-life of carbon-14 is 5,720 years, thus, we can calculate λ using the second equation, and then find t.

Solving the second equation for t, and using the λ we have just calculated we will have
t= 7665 years
Answer:
Because scientists call vaccines reagents.