Answer: a) %(C/Co) = (e^(-0.027t)) × 100
b) t1/2 = 25.67years
c) 5.872%
Explanation:
a) Radioactive reactions always follow a first order reaction dynamic
Let the initial concentration of Strontium-90 be Co and the concentration at any time be C
The rate of decay will be given as:
(dC/dt) = -KC (Minus sign because it's a rate of reduction)
The question provides K = 2.7% per year = 0.027/year
(dC/dt) = -0.027C
(dC/C) = -0.027dt
∫ (dC/C) = -0.027 ∫ dt
Solving the two sides as definite integrals by integrating the left hand side from Co to C and the Right hand side from 0 to t.
We obtain
In (C/Co) = -0.027t
(C/Co) = (e^(-0.027t))
In percentage, %(C/Co) = (e^(-0.027t)) × 100
(Solved)
b) Half life of a first order reaction (t1/2) = (In 2)/K
K = 0.027/year
t1/2 = (In 2)/0.027 = 25.67 years
c) percentage that remains after 105years,
%(C/Co) = (e^(-0.027t)) × 100
t = 105
%(C/Co) = (e^(-0.027 × 105)) × 100 = 5.87%
Answer:
1,100 km/h
Explanation:
Velocity = distance/time = 4,400 km / 4.0 h = 1,100 km/h
Answer: the formation of ester is an exothermic reaction.. therefore, decreasing the temperature will make the reaction proceed forward, producing more esters
Explanation:
Answer : Option D) Hot and dry with low growing shrubs.
Explanation : According to the attached image of the Biome, this particular biome displays the hot and dry climatic region along with low growing shrubs. A biomes are the way to divide the largely occurring flora and fauna in a particular place on the Earth's surface. These divisions are made on the basis of climatic patterns, soil types, and the animals and plants that are found to inhabit in that area.
Answer:
Because the specific heat of the metal is less than the specific heat of water.
Explanation:
Hello, happy to help you today!
In this case, we need to analyze a property called "specific heat" which accounts for how much energy is required to increase or decrease the temperature of 1 g of the substance by 1 °C.
In this case, since the specific heat of water is about 4.184 J/g°C and the specific heat of metals in general is greater than zero, of course, but less than one, we can infer that for the same amount of energy, when they are in contact, more grams of metal will be cooled down to those of water heated up, because the specific heat of the metal is less than the specific heat of water.
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