Answer:
2.447 × 10⁴ years
Explanation:
Step 1: Given data
- Half-life of the radioactive atom (t1/2): 3,500 years
- Parent-daughter ratio ([A]/[A]₀): 1:127 (1/127)
Step 2: Calculate the rate constant
Radioactive decay follows first-order kinetics. We can calculate the rate constant (k) using the following equation.
k = ln2 / (t1/2) = ln2 / 3,500 y = 1.980 × 10⁻⁴ y⁻¹
Step 3: Calculate the time elapsed (t)
For first-order kinetics, we will use the following expression.
ln ([A]/[A]₀) = -k × t
t = ln ([A]/[A]₀)/ (-k)
t = ln (1/127) / (1.980 × 10⁻⁴ y⁻¹) = 2.447 × 10⁴ y
Answer: According to the first law of thermodynamics, energy can be transferred from place to place or changed between different forms, but it cannot be created or destroyed. For instance, light bulbs transform electrical energy into light energy, and gas stoves transform chemical energy from natural gas into heat energy.
Explanation:
Answer:
Water along with carbon dioxide and oxygen are the agents of chemical weathering to support that statement.
Explanation:
- Chemical weathering is the continuous process that makes the rocks weak and decompose by changing its composition.
- Water is the main agent for chemical weathering, the molecules of water separates the ions from their existing compounds and edges them.
- Water has the ability to completely dissolve some minerals. for example, salt.
- Oxygen also takes part in chemical weathering by the process called as oxidation.
- Similarly carbon dioxide initiates weathering by the acid rain.
Answer:Thus we can conclude that these charcoal fragments are about 11460 years old.
Explanation:
a) for completion of half life:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
Expression for rate law for first order kinetics is given by:
where,
k = rate constant
t = age of sample
a = let initial amount of the reactant = 100
a - x = amount left after decay process = 25
b) for completion of 75 % of reaction
Thus we can conclude that these charcoal fragments are about 11460 years old.
