It’s atomic mass is what the number means.
Answer:
The half life is 
Explanation:
The half life of a first order reaction is mathematically represented as
Substituting 
for the rate constant
<span>pm stands for picometer and picometers are units which can be used to measure really tiny distances. One picometer is equal to 10^{-12} meters. We know that one centimeter is equal to 10^{-2} m so there are 10^2 cm per meter.
We can change the distance d = 115 pm to units of centimeters.
d = (115 pm) x (10^{-12}m / pm) x (10^2 cm / m)
d = 115 x 10^{-10} cm = 1.15 x 10^{-8} cm
The distance in centimeters is 1.15 x 10^{-8} cm</span>
D- seismic waves
Geologists use an indirect method to study Earth's interior. Earthquakes produce seismic waves. Geologists record the seismic waves and study how they travel through Earth.
