The appropriate response is gamma radiation. Alpha particles can be halted via air. UV radiation can be halted by a typical layer of clothing.Beta particles can be ceased by the thick plastic suit. Just gamma radiation can enter the substantial suit. It must be halted by thick dividers of lead or cement.
B
. They are large and occur at shallow depths near the where the plates diverge.
<span>NPK ratio system is a conventional shorthand for the ratio of the nitrogen N), phosphorus (P) and potassium (K) in a fertilizer. It actually shows amount of P</span>₂O₅.
If we use 100 kg of P₂O₅:
m(P₂O₅) = 0,15 · 100 kg.
m(P₂O₅) = 15 kg.
m(P₂O₅) : M(P₂O₅) = m(P) : 2M(P).
15 kg : 142 = m(P) : 62.
m(P) = 6,55 kg.
ω(P) = 6,55 kg ÷ 100 kg · 100% = 6,55%.
Answer:
Option A
Explanation:
Addition of too much of solvent will make the solution dilute due to which the crystals will not form. Hence option D is incorrect
On the other hand adding a minimum amount of boiling solvent will give a saturated solution for recrystallization. Hence, option A is incorrect
Addition of cold solvent will lower the rate of formation of crystals. Hence, both option B and C are incorrect
Answer:
1.146 x 10⁴ year.
Explanation:
- The decay of carbon-14 is a first order reaction.
- The rate constant of the reaction (k) in a first order reaction = ln (2)/half-life = 0.693/(5730 year) = 1.21 x 10⁻⁴ year⁻¹.
- The integration law of a first order reaction is:
<em>kt = ln [A₀]/[A]</em>
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k is the rate constant = 1.21 x 10⁻⁴ year⁻¹.
t is the time = ??? years.
[A₀] is the initial percentage of carbon-14 = 100.0 %.
[A] is the remaining percentage of carbon-14 = 1/4[A₀] = 25.0 %.
∵ kt = ln [Ao]/[A]
∴ (1.21 x 10⁻⁴ year⁻¹)(t) = ln (100.0%)/[25.0 %]
(1.21 x 10⁻⁴ year⁻¹)(t) = 1.386.
∴ <em>t </em>= 1.386/
(1.21 x 10⁻⁴ year⁻¹) = <em>1.146 x 10⁴ year.</em>
