Answer:
(B) 73.0 hours.
Explanation:
- It is known that the decay of a radioactive isotope isotope obeys first order kinetics.
- Half-life time is the time needed for the reactants to be in its half concentration.
- If reactant has initial concentration [A₀], after half-life time its concentration will be ([A₀]/2).
- Also, it is clear that in first order decay the half-life time is independent of the initial concentration.
<em>So, the half-life of 201Tl when its concentration is 0.0136 M is (B) 73.0 hours.</em>
Option A. Smaller atoms and stronger bonds.
Smaller the size of the atoms, less will be the distance between positive charge nucleus of one atom and electrons (negative charge) of other atom. This results in strong interaction between them.
Also, stronger bonds are difficult to break, making the minerals harder. Thus, small atoms and strong bonds in minerals makes then harder than the minerals with weak bonds or larger atoms.
C₁ * V₁ = C₂ * V₂
1.0 * 20 = C₂ * 60
20 = C₂ * 60
C₂ = 20 / 60
C₂ = 0.33 M
hope this helps!
Answer: -
The hydrogen at 10 °C has slower-moving molecules than the sample at 350 K.
Explanation: -
Temperature of the hydrogen gas first sample = 10 °C.
Temperature in kelvin scale of the first sample = 10 + 273 = 283 K
For the second sample, the temperature is 350 K.
Thus we see the second sample of the hydrogen gas more temperature than the first sample.
We know from the kinetic theory of gases that
The kinetic energy of gas molecules increases with the increase in temperature of the gas. The speed of the movement of gas molecules also increase with the increase in kinetic energy.
So higher the temperature of a gas, more is the kinetic energy and more is the movement speed of the gas molecules.
Thus the hydrogen at 10 °C has slower-moving molecules than the sample at 350 K.