Answer:
12.213 minutes will be taken for 120 g-Thalium-208 to decay to 75 grams.
Explanation:
Radioactive isotopes decay exponentially in time, the mass of the isotope ([tex]m(t)[/tex]), in grams, is described by the formula in time ([tex]t[/tex]), in minutes:
[tex]m(t) = m_{o}\cdot e^{-\frac{t}{\tau} }[/tex] (1)
Where:
[tex]m_{o}[/tex] - Initial mass of the isotope, in grams.
[tex]\tau[/tex] - Time constant, in minutes.
In addition, the time constant associated with the isotope decay can be described in terms of half-life ([tex]t_{1/2}[/tex]), in minutes:
[tex]\tau = \frac{t_{1/2}}{\ln 2}[/tex] (2)
If we know that [tex]m(t) = 7.5\,g[/tex], [tex]m_{o} = 120\,g[/tex] and [tex]t_{1/2} = 3.053\,min[/tex], then the time taken by the isotope is:
[tex]\tau = \frac{t_{1/2}}{\ln 2}[/tex]
[tex]\tau = \frac{3.053\,min}{\ln 2}[/tex]
[tex]\tau \approx 4.405\,min[/tex]
[tex]t = -\tau \cdot \ln \frac{m(t)}{m_{o}}[/tex]
[tex]t = -(4.405\,min)\cdot \ln \left(\frac{7.5\,g}{120\,g} \right)[/tex]
[tex]t \approx 12.213\,min[/tex]
12.213 minutes will be taken for 120 g-Thalium-208 to decay to 75 grams.
12.21 minutes will it take for 120 g of Thallium-208 to decay
to 7.5 g.
What is half life period?Half life period is that time in which half of the reactant is convert into product.
In the question it is given that,
Initial mass of Thallium-208 = 120g
Final mass after decay = 7.5g
And half life of this decay = 3.053 min
Here we can calculate the total time of decay by the formula : T = t × n.
Where, T = total required time
t = half life
n = no. of half life required to decompose reactant.
120 → 60 →30 → 15 → 7.5
From the above sequence it is clear that we require 4 times of half life to decompose 120g to 7.5g.
So, T = 3.053 × 4 = 12.21 minutes
Hence, 12.21 minutes will it take to decay.
To learn more about half life, visit below link:
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The image shows a diagram of a chloroplast, which captures light energy from thesun. In what type of cell would you expect to find these
organelles?
Answer: a plant cell
Explanation:
how many teaspoons of jelly would be required to use 36 slices of bread?
Answer:
depends on how much jelly u like
A mass of 68.45 g of nickel (II) sulfate hydrate, NiSO4∙ nH2O, loses 28.40 g upon dehydration. What is the hydration number of this compound? (Find n.)
Answer:
n=4
Explanation:
n= (154.75×28.40)÷(68.45×18)
n=3.5
n=4(approximately)
Which chemical reaction is the fastest?
A. Oven cleaner absorbs cooked grease overnight.
B. Cake rises as it cooks in the oven.
C. Drain cleaner fizzes up as it encounters blockages in a pipe.
D. Milk turns sour.
Answer:
C) drain cleaner fizzes up as it encounters blockages in a pipe
Explanation:
The saturation point for a solution is 25.0 grams of solute per 500 grams of solvent. If you pour 50.0 grams of solute into 800. grams of solvent, how many grams of
solute are in solution?
Plz help me!!
Answer:
I think 50 grams only because you have pour 50 grams of solute in to 800 grams of solvent.
Explain the role of a primary consumer and a secondary consumer in a food web.
Answer:
Explanation:
Secondary consumers are organisms that eat primary consumers for energy. Primary consumers are always herbivores, or organisms that only eat autotrophic plants.
Carnivores only eat other animals, and omnivores eat both plant and animal matter.
Gary wanted to find out if some food colourings contained a banned food dye.
He put a drop of each food colouring and the banned food dye onto some special paper.
He hung the paper in a beaker of water.
After 10 minutes, the banned food dye and some of the dyes from the food colourings had moved up the paper.
Gary’s results are shown below.
(a) Gary wrote the labels on the paper in pencil. Why should he not write them in ink?
Explanation:
njsnjsjiwnaibainaondodnodn9nsine8ni
water, soil, temperature, space
Answer:
wdym??
Explanation:
Answer:
wdym by water, soil, temperature, space?
1
Which of the following is a mixture?
A air
B copper
C oxygen
D steam
Answer:
A air
Explanation:
Air is a mixture but not compound. Its constituents can be separated. For example: oxygen, nitrogen etc. by physical process.
explain how the alpha particle scattering experiment led to a change in the model of the atom from the plum pudding model?
Answer:
So originally, the plum pudding model by J.J Thomson is electrons (negatively charged) held in place by a proton (positively charged) cloud.
Alpha particles are positively charged made of 2 protons + 2 neutrons.
Rutherford's experiment where they beamed those positively charged alpha particles demonstrated that an atom was not a uniform cloud, instead the alpha particles that were deflected was the positively charged nucleus. The alpha particles would also pass through if it didn't hit the nucleus, or be slightly attracted to the negative charge on the electrons. But the overall idea is that Rutherford's experiment changed what the structure of the atom was by discovering that they have a positively charged nucleus due to the deflection of positively charged alpha particles.
How many grams of Mg would be needed to react with 6.0 moles HCl?
Answer:
72g
Explanation:
The balanced equation of the reaction between Magnesium (Mg) and hydrochloric acid (HCl):
Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
Based on this equation, 1 mole of Mg needs to react with 2 moles of HCl.
Hence, 6 moles of HCl will need to react with 6 × ½ = 3 moles of Mg.
Using the formula; mole = mass/molar mass
Molar mass of Mg = 24g/mol
3 = mass/24
mass = 72g.
The reaction O3 + NO → O2 + NO2 has Ea = 10.7 kJ/mole and ΔH = – 199.8 kJ/mole. What is the activation energy for the following reaction?
O2 + NO2 → O3 + NO
Answer:
Ea = 210.5kJ/mole
Explanation:
When the reaction:
O3 + NO → O2 + NO2
Occurs, requires 10.7kJ/mole and releases -199.8kJ/mole.
For the forward reaction:
O2 + NO2 → O3 + NO
The Ea is the sum of Ea of the forward reaction and - ΔH, that is:
Ea = Ea - (-ΔH)
Ea = 10.7kJ/mol - (-199.8kJ/mol)
Ea = 210.5kJ/mole
A toy balloon is filled to 135 mL at a temperature of 22.5 °C (295.5 K). What temperature in Kelvin does it need to be heated to expand to 250 mL?
Answer:
T2 = 547.2K
Explanation:
Given:
V1 = 135 ml. V2 = 250 ml
T1 = 295.5K. T2 = ?
Using Charles's law and solving for T2,
V1/T1 = V2/T2
T2 = (V2/V1)T1
= (250 ml/135 ml)(295.5K)
= 547.2K (or 273.2°C)
How many moles of KCl are produce when 61.5 g of KClO3 are decomposed?
Answer:
0.502mol
Explanation:
The balanced chemical equation of the reaction described in this question is as follows:
2KClO3 → 2KCl+ 3O2
According to the equation above, 2 moles of KClO3 will produce 2 moles of KCl.
Using mole = mass/molar mass to convert mass of KClO3 to moles
Molar mass of KClO3 = 39 + 35.5 + 16(3)
= 39 + 35.5 + 48
= 122.5g/mol
mole = 61.5 g ÷ 122.5g/mol
mole = 0.502mol
Since 2 moles of KClO3 will decompose to produce 2 moles of KCl.
0.502 mol of KClO3 will decompose to produce 0.502 × 2/2
= 0.502mol of KCl.
. Water is one of our most important resources. Only about 1% of the Earth's water is for human needs. Name four ways you can help conserve water. This is for science btw...
Answer:please see explanation for answers
Explanation:
Water conservation is an approach geared towards controlling how water is used. Because of the ever growing population, which weighs so much on water available to mankind,Over negligence and abuse of our water resources have been a great point of concern, that is why the need for the knowledge of water conservation is preached.
Now, some of the ways we can conserve water include
1. Putting off taps while lathering the hands with soap
2.use of irrigation system to water crops and plants
3.. while brushing, make sure to turn off the tap or faucet
4. use a shower rather than a bath
NO LINKS!!!!!!!!
how many joules are needed to heat 20g of Cu from 10 to 50 degrees C?
Answer:
q=309.6 J
Explanation:
Here we'll be using the formula of specific heat capacity: Q=mcΔT
Q= heat (joules)
m=mass (g)
c=specific heat capacity
ΔT= change in temperature > Final temp. - initial temp.
Let's plug in what we know and solve for q=heat.
q=(20)(0.387)(50-10)
q=(20)(0.387)(40)
q=309.6 joules
Depending on your teacher and the problem, they might want you to keep the temperature in C. Mine wanted them all in Kelvin, so if we were to convert it to Kelvin it would be:
273 + 40= 313 K
q=(20)(0.387)(313)
q=2422.6 J
Which gas variable has to do with the amount of collisions of gas particles has?
(I think it’s temperature but I’m not sure)
Pressure
Temperature
Amount
Volume
What is the change in energy of a gas at a pressure of 105 kPa, if 245 J of energy is added causing a change in volume from 25.3 L to 38.6 L?
Answer:
-1151.5 J
Explanation:
Given that:
The supplies energy = 245 L
The energy used in the expansion of gas = Pressure ×ΔV (change in volume)
At standard conditions;
Pressure = 105 × 10³ Pa
energy used in the expansion = 105 × 10³ Pa × (38.6 - 25.3)L
= 1396.5 J
Thus, the change in the energy of gas = 245 - 1396.5 J
= -1151.5 J
Hence, we can conclude that the gas has lost its own energy in the process of expansion.
If 18.6 g of methanol is used to dissolve 2.68 g of Hg(CN)2, what is the molality of the solution?
Answer:
I searched it up and screenshot it
Explanation:
I searched it up : )
Derive Boyle's law.
i'll mark the brainliest for the answer
Answer:
According to Boyle's Law, an inverse relationship exists between pressure and volume. ... The relationship for Boyle's Law can be expressed as follows: P1V1 = P2V2, where P1 and V1 are the initial pressure and volume values, and P2 and V2 are the values of the pressure and volume of the gas after change.
Hope that helps! :)
-Aphrodite
Explanation:
A sample of water vapor condenses to form liquid water. What change in water
allows this to happen?
Answer:
Condensation is the process of water vapor condensing into liquid water.
Explanation:
"Water condenses on a can of cold soda. Water vapor in the air reaches its dew point as it cools in the air around the can, forming liquid drops of water. Condensation is the process where water vapor becomes liquid. It is the reverse of evaporation, where liquid water becomes a vapor." -National Geographic"
PLEASE HELP!!!! What is the molarity of a solution that contains 42.9g of calcium chloride in a 45.0L solution?
How much pressure (in atm) would be found in 5.8 moles of an ideal gas at 358 K and volume of 3.9 L?
Answer:
pressure=force / volume
5.8÷3.9
=1.5 ml
WILL DO ANY THING TO GET A HELPWhich type of wind occurs over a small area?
Question 3 options:
polar easterlies
the Coriolis effect
trade winds
sea breezes
Answer: Sea breezes
Explanation: Took the test
I NEED NOW PLEASE HELP How many grams of KF are need in order to produce 2.0 mol CaF?
What do the particles of water look like at A and B? A. B. C. D.
Answer:
Explanation:
Each particle, or corpuscle, of water is a regular icosahedron (20-sided geometrical solid). This is what water particles look like, according to Plato's description in the Timaeus. In the center is the water-particle Plato describes at 55b, with 6 scalene triangles making up each equilateral face of the icosahedron
ito Ang naimbento ni graham bell na nagpabilis sa pakikupagtalastasan
Answer:
ФОТОГРОФИРУЙ
ИЛИ НАПИШИ
В КОМЕНТЫ
An artificial biosphere is an enclosed area that contains the elements necessary for human life to exist. Suppose scientists want to develop an artificial biosphere on a new planet. The new planet has an atmosphere that is 96% carbon dioxide with only trace amounts of oxygen. What could humans do to make enough oxygen to survive? Explain your answer.
Answer:
See Explanation
Explanation:
A biosphere is a zone of life found on earth. Since the artificial biosphere has all the elements that support and sustain human life, then there must also be soil in the artificial biosphere.
If that is the case, then we can engage in massive tree planting. Trees take in carbon dioxide and release oxygen. Hence if a large number of trees are planted all over the artificial biosphere, the trees will eventually produce large enough oxygen to support human life overtime.
An unknown substance has the chemical formula: Fez(C204)3 A molecule of the unknown substance contains A 3 fluorine atoms, 2 calcium atoms, and 4 oxygen atoms. 2 iron atoms, 6 carbon atoms, and 12 oxygen atoms. , 2 iron atoms, 2 carbon atoms, and 12 osmium atoms. 1 fluorine atom, 2 europium atoms, 8 copper atoms .
Answer:
Explanation: It is an ionic compound Fe2(C2O4)3
The compound with the formula Fe₂(C₂O₄)₃ contains two iron atoms, 6 carbon atoms and 12 oxygen atoms. Thus option C is correct.
What is chemical formula?Chemical formula of a compound or molecule represent the identity of the compound by representing which atoms are present in how many numbers.
Chemical formula is significant in representing a compound and distinguish it from other compounds.The number of each atom are given as subscripts for the symbol of each atoms.
If any group of atoms such SO₄ group or CO₃ group repeats in the compound put them in brackets and their number is given outside.The compound Fe₂(C₂O₄)₃ contains 2 iron atoms because Fe is the symbol of iron.
C₂O₄ is oxalate group and it is 3 in number. Two carbon and 4 oxygens are there in one oxalate group. Thus there are total 6 carbons and 12 oxygens in 3 oxalate groups. Hence option C is correct.
To find more about chemical formula, refer the link below:
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#SPJ2
Hey I know this looks easy but
Can somebody plz help tell me where to put the organisms in the correct group (only if u know which ones) thanks :3
WILL MARK BRAINLIEST WHOEVER ANSWERS FIRST :DDD!
Answer:
Benthos: crabs, starfish, lobsters, stingrays,, algae
Plankton: diatom, tubeworms
Nekton: whales, sharks, turtles,
Explanation: