Radio active decay reactions follow first order rate kinetics.
a) The half life and decay constant for radio active decay reactions are related by the equation:



Where k is the decay constant
b) Finding out the decay constant for the decay of C-14 isotope:



c) Finding the age of the sample :
35 % of the radiocarbon is present currently.
The first order rate equation is,
![[A] = [A_{0}]e^{-kt}](https://tex.z-dn.net/?f=%20%5BA%5D%20%3D%20%5BA_%7B0%7D%5De%5E%7B-kt%7D%20%20%20)
![\frac{[A]}{[A_{0}]} = e^{-kt}](https://tex.z-dn.net/?f=%20%5Cfrac%7B%5BA%5D%7D%7B%5BA_%7B0%7D%5D%7D%20%3D%20e%5E%7B-kt%7D%20%20)


t = 7923 years
Therefore, age of the sample is 7923 years.
Answer:
F = 30 N
Explanation:
Given data:
Mass of toy train = 1.5 kg
Acceleration of train = 20 m/s²
Amount of force acting on it = ?
Solution:
The net force on object is equal to the its mass multiply by its acceleration.
Formula:
F = ma
F = force
m = mass
a = acceleration
Now we will put the values in formula.
F = 1.5 kg × 20ms⁻²
F = 30 kg.ms⁻²
kg.ms⁻² = N
F = 30 N
Answer:
Rate = k [OCl] [I]
Explanation:
OCI+r → or +CI
Experiment [OCI] M I(-M) Rate (M/s)2
1 3.48 x 10-3 5.05 x 10-3 1.34 x 10-3
2 3.48 x 10-3 1.01 x 10-2 2.68 x 10-3
3 6.97 x 10-3 5.05 x 10-3 2.68 x 10-3
4 6.97 x 10-3 1.01 x 10-2 5.36 x 10-3
The table above able shows how the rate of the reaction is affected by changes in concentrations of the reactants.
In experiments 1 and 3, the conc of iodine is constant, however the rate is doubled and so is the conc of OCl. This means that the reaction is in first order with OCl.
In experiments 3 and 4, the conc of OCl is constant, however the rate is doubled and so is the conc of lodine. This means that the reaction is in first order with I.
The rate law is given as;
Rate = k [OCl] [I]
The correct answer here is C. Dew forms on the grass.
Water is a polar substance, which means it has many unique properties. One of which, is its ability to adhere and cohere to surfaces and substances. This particular question is asking about the cohesive properties of water, meaning it’s ability to stick to itself (through bonding.) The only answer choice that represents a situation where water is linking up with other molecules of water are dew drops. The water comes together using cohesion to form the drop and hen the water’s high surface tension properties meet the dew drop’s shape. The other answer choices describe alternate processes like: freezing, melting, and evaporation, respectively.
I hope this helps! :)