Answer: The time for activity to fell from 800 counts per second to 200 counts per second is 20 minutes
Explanation:
Expression for rate law for first order kinetics is given by:
[tex]t=\frac{2.303}{k}\log\frac{a}{a-x}[/tex]
where,
k = rate constant
t = age of sample
a = let initial amount of the reactant
a - x = amount left after decay process
a) for finding the rate constant:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
[tex]t_{\frac{1}{2}}=\frac{0.693}{k}[/tex]
[tex]k=\frac{0.693}{10min}=0.0693min^{-1}[/tex]
b) for activity to fell from 800 counts per second to 200 counts per second.
[tex]t=\frac{2.303}{0.0693}\log\frac{800}{200}[/tex]
[tex]t=20minutes[/tex]
The time for activity to fell from 800 counts per second to 200 counts per second is 20 minutes
Explain how most fish reproduce similarly?
Answer:
Fishes undergo both asexual and sexual mode of reproduction with majority of fishes reproducing by sexual mode
Explanation:
Fishes undergo sexual reproduction. The sperm from the male fuses with the eggs of females. Some of the fishes have separate female and male sexes while some are hermaphrodites and have both testes and ovaries. Some species of fishes reproduce through parthenogenesis in which female egg develops into baby fishes without fusing with a sperm cell. Due to this, the offspring are exact copies of their mothers
if I have 22.1 grams of CO2 gas at -188 degrees Celsius and 165 ml what is the pressure of the gas in kPa
Answer:
P = 2.145kPa
Explanation:
Mass = 22.1g
Molar mass of CO2 = 44g/mol
Vol = 165mL = 0.165L
T = -188°C = (-188 + 273.15)K = 85.15K
R = 8.314J/mol.K
From ideal gas equation,
PV = nRT
P = pressure of the ideal gas
V = volume the gas occupies
n = number of moles if the gas
R = ideal gas constant
T = temperature of the gas
n = number of moles
n = mass / molar mass
n = 22.1 / 44 = 0.50moles
PV = nRT
P = nRT/ V
P = (0.5 × 8.314 × 85.15) / 0.165
P = 2145.26Pa = 2.145kPa
Pressure of the gas is 2.145kPa
How many atoms of each element are in the chemical formula......
CA(OH)2
A.1 calcium, 1 oxygen, and 1 hydrogen
B.1 calcium, 2 oxygen, and 2 hydrogen
C.2 calcium, 1 oxygen, and 2 hydrogen
D.2 calcium, 2 oxygen, and 2 hydrogen
Answer:
Option B. 1 calcium, 2 oxygen, and 2 hydrogen
Explanation:
The number of each atoms present in Ca(OH)2 can be summarised as follow:
Calcium (Ca) = 1
Oxygen (O) = 2
Hydrogen (H) = 2
From the above illustration, we can see clearly that Ca(OH)2 contains 1 calcium, 2 oxygen and 2 hydrogen.
Answer:
1 calcium, 2 oxygen, and 2 hydrogen
1 calcium, 2 oxygen, and 2 hydrogen
1 calcium, 2 oxygen, and 2 hydrogen
1 calcium, 2 oxygen, and 2 hydrogen
1 calcium, 2 oxygen, and 2 hydrogen
1 calcium, 2 oxygen, and 2 hydrogen
1 calcium, 2 oxygen, and 2 hydrogen
XD
Explanation:
Why do solids expand on heating?
Explanation:
The molecules of solids are shrinked in there normal state . but as a heat energy is produced , the molecules starts curating fast and fast as temperature goes up . since they vibrate , they hit and collide each other breaking the bondings this increases the surface of area of the solid , and molecules consumes that space and they expand .
HA and HB are two strong monobasic acids. 25.0cm3 of 6.0mol/dm3 HA is mixed with 45.0cm3 of 3.0mol/dm3 HB.
What is the H+ (aq) concentration in mol/dm3 in the resulting solution ?
A 1.9
B 2.1
C 4.1
D 4.5
If anyone could explain how to reach an answer that would be so helpful !!
Answer:
The H+ (aq) concentration of the resulting solution is 4.1 mol/dm³
(Option C)
Explanation:
Given;
concentration of HA, [tex]C_A[/tex] = 6.0mol/dm³
volume of HA, [tex]V_A[/tex] = 25.0cm³, = 0.025dm³
Concentration of HB, [tex]C_B[/tex] = 3.0mol/dm³
volume of HB, [tex]V_B[/tex] = 45.0cm³ = 0.045dm³
To determine the H+ (aq) concentration in mol/dm³ in the resulting solution, we apply concentration formula;
[tex]C_iVi = C_fV_f[/tex]
where;
[tex]C_i[/tex] is initial concentration
[tex]V_i[/tex] is initial volume
[tex]C_f[/tex] is final concentration of the solution
[tex]V_f[/tex] is final volume of the solution
[tex]C_iV_i = C_fV_f\\\\Based \ on \ this\ question, we \ can \ apply\ the \ formula\ as;\\\\C_A_iV_A_i + C_B_iV_B_i = C_fV_f\\\\C_A_iV_A_i + C_B_iV_B_i = C_f(V_A_i\ +V_B_i)\\\\6*0.025 \ + 3*0.045 = C_f(0.025 + 0.045)\\\\0.285 = C_f(0.07)\\\\C_f = \frac{0.285}{0.07} = 4.07 = 4.1 \ mol/dm^3[/tex]
Therefore, the H+ (aq) concentration of the resulting solution is 4.1 mol/dm³
what does it mean to say that momentum is conserved
It means that in any interaction where external impulses don't occur, the momentum of the system remains the same before and after the interaction. When a cannonball is fired, its momentum does change.
what is an atom
plz help
Answer:
the smallest thing in the world
Explanation:
Answer:
It is the smallest particle of the elements that exists ob the earth
Most of the costs associated with using renewable resources are due to
a. overuse of resources
b. atmospheric pollution
C. lack of availability
d. global warming
Please select the best answer from the choices provided
A
B
С
OD
Answer:
a. overuse of resources is the correct answer.
Explanation:
Renewable resources are available and they are abundant but overuse of these renewable resources will have a negative effect on the surroundings and humans.
Overuse of renewable resources will leads to the depletion of these renewable sources in the future and will also make the ecosystem unbalance.
Renewable resources are solar energy, geothermal energy, biomass energy, wind energy, hydro energy.
Thus renewable resources are threatened due to overuse and it must be carefully used.
A 2-column table with 3 rows. Column 1 is labeled Substance with entries upper O subscript 2, upper N subscript 2, upper C upper O subscript 2. Column 2 is labeled Molar mass with entries 32.00 grams per mole, 28.02 grams per mole, and, 44.02 grams per mole.
For each pair below, select the sample that contains the largest number of moles.
Pair A
2.50 g O2
2.50 g N2
Answer:
2.50 g N2 and the second one is 21.5 g N2
Explanation:
just answered it and it was correct
If 500.0 mL of 0.450 M sodium phosphate is reacted with an excess of iron (II) nitrate solution, how many grams of iron (II) phosphate are produced?
Answer:
If 500.0 mL of 0.450 M sodium phosphate is reacted with an excess of iron (II) nitrate solution, how many grams of iron (II) phosphate are produced?
idk
Explanation:
Answer:
164.2726 g
The ratio in the equation is 3:1 so the limit reaction ratio is 3:1 therefore, 0.392456 mol of were reaction.
Brainlist pls!
A student claims that if she wanted to make a solution quickly, she should use small pellets instead of powder along with heating and stirring. Do you agree or disagree with the student's claim? Answer using CER format. PLS HELP I’m a little confused and don’t know what to put.
Answer:
I disagree with the student's claim
Explanation:
From basic chemistry, the rate of chemical reaction increases with an increased surface area.
This simply means that a powdered substance will react faster than a small pellet of the same substance.
Let us break this down further. The pellet has a smaller exposed surface per grain to the solvent, here is how. Imagine the powdered substance bunched up together to make the small pellet, grains at the center of the pellet is blocked by other grains around it, and will take time before it comes in contact with the solvent. For the powdered grains, each grain has a surface independently exposed to the solvent and can easily come in contact with the solvent, taking less time to react with the solvent.
Technically, a powdered substance has more exposed surface area and logically will take a shorter time for the reaction to be complete.
A sample of gas occupies 100.0 mL at standard pressure. What volume will the gas occupy at a pressure of 80.0 mm Hg if the temperature remains constant? *
Answer:
950mL
Explanation:
The following were Data were obtained from the question:
Initial volume (V1) = 100mL
Initial pressure (P1) = stp = 760mmHg
Final pressure (P2) = 80mmHg
Final volume (V2) =..?
The final volume of the gas can be obtained by using the Boyle's law equation as follow:
P1V1 = P2V2
760 x 100 = 80 x V2
Divide both side by 80
V2 = (760 x 100) /80
V2 = 950mL
Therefore, the new volume of the gas is 950mL
Which compound is part of the structure of another compound listed?
A. amino acids
B. nucleic acids
C. proteins
Answer:
i think its a
Explanation:
nucleic acids are dna and rna
amino acids are the 4 nuecleotides in dna or rna
Answer:
amino acids i think
Explanation:
If I add water to 100mL of a 0.15 M NaOH solution until the final volume is 150mL, what will the molarity of the diluted solution be?
Answer: The molarity of the diluted solution be 0.10 M
Explanation:
According to the dilution law,
[tex]C_1V_1=C_2V_2[/tex]
where,
[tex]C_1[/tex] = concentration of concentrated solution = 0.15 M
[tex]V_1[/tex] = volume of concentrated solution = 100 ml
[tex]C_2[/tex] = concentration of diluted solution= ?
[tex]V_2[/tex] = volume of diluted solution= 150 ml
Putting the values we get:
[tex]0.15\times 100=M_2\times 150[/tex]
[tex]M_2=0.10M[/tex]
Thus the molarity of the diluted solution be 0.10 M
what do I do when my dog ate my secret 10 pound stash of chocolate and he won't move please help what do i do oh god help me pls
Answer:
call an vet ASAP 10 pounds of chocolate is very bad for a dog.
Explanation:
Chocolate is one of the worst things a dog can eat, and 10 pounds of it is worst! Take your dog to the vet IMMEDIATELY! I hope that that the dog will survive.
-------------------------------------------------------------------------------------------------------------Brainiest would make my day, but you don’t have to give it! You’re welcome.
Which is an example of a beneficial mutation? ANSWER AND ILL GIVE BRAINLY POINTS !!!!!! HELP ASAP !
Answer:
Some humans are randomly immune to malaria or have increased bone density due to random beneficial mutations.
Explanation:
Answer: one that changes the color of a rabbit, allowing it to hide from predators.
Explanation:Hey give me brainliest award need it
What is the formula for an ionic compound that is composed of potassium and oxygen?
Answer:
Ty for free points :)
Explanation:
6. How much water must be added to 600 mL of a 0.15 mol/L Ca(OH); solution
to make a solution with a concentration of 0.10 mol/L? (4 marks)
Answer:
300mL
Explanation:
To obtain the volume of water added, let us calculate the volume of the diluted solution.
Data obtained from the question include:
Molarity of stock solution (M1) = 0.15mol/L
Volume of stock solution (V1) = 600mL
Molarity of diluted solution (M2) = 0.1mol/L
Volume of diluted solution (V2) =..?
The volume of the diluted solution can be obtained as follow:
M1V1 = M2V2
0.15 x 600 = 0.1 x V2
Divide both side by 0.1
V2 = 0.15 x 600 / 0.1
V2 = 900mL.
Therefore the volume of the diluted solution is 900mL.
Finally, we can obtain the volume of the water added by calculating the difference in the volume of the diluted solution and that of the stock solution. This is illustrated below:
Volume of stock solution (V1) = 600mL
Volume of diluted solution (V2) = 900mL
Volume of water added =...?
Volume of water added = V2 – V1
Volume of water added = 900 – 600
Volume of water added = 300mL
Therefore, the volume of water added is 300mL
Which substance will contain the strongest bond between the two carbon atoms?
A. ethane, H3CCH3
B. ethene, H2CCH2
C. ethyne, HCCH.
D. chloroethene, H2CCHCl
Answer:
b
Explanation:
Ethyne will contain the strongest bond between the two carbon atoms as the triple bonds are the strongest.
What is an atom?An atom is defined as the smallest unit of matter which forms an element. Every form of matter whether solid,liquid , gas consists of atoms . Each atom has a nucleus which is composed of protons and neutrons and shells in which the electrons revolve.
The protons are positively charged and neutrons are neutral and hence the nucleus is positively charged. The electrons which revolve around the nucleus are negatively charged and hence the atom as a whole is neutral and stable due to presence of oppositely charged particles.
Atoms of the same element are similar as they have number of sub- atomic particles which on combination do not alter the chemical properties of the substances.
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Chemistry Problem
1234567890-
Answer:
what?
Explanation:
whats the answer
Answer:
oh yea! keep up the great work buddy!!
Which of the following shows the solution set to the quadratic equation 8x2+40x=0
Answer:
Option 2
Explanation:
There are many ways to do it. You can also just use your scientific calculator to directly get the answer. But now I'm going to solve the equation by factoring.
8x² + 40x = 0
Factor out 8x from the expression
8x ( x + 5 ) = 0
Divide both sides by 8
8x ( x + 5 ) ÷8 = 0 ÷8
x ( x + 5 ) = 0
Now we have two factors, x & x+5. Set each factors equal to zero
x = 0
x + 5 = 0
Now solve the equation
x = 0
x = -5
Then you get the answer!
The Earth's diameter at the equators is _____ its diameter at the poles. A:greater than B:equal to C:less than
Please help!!!
Which layer of the sun is shown extending into space in the picture above?
Group of answer choices
Corona
Radiative zone
Convective zone
Photosphere
Answer:
Corona
Explanation:
Is the answer so yeah...
Which word equation shows hydrogen reacting with oxygen to form water?
oxygen + water Right arrow. hydrogen
hydrogen + oxygen Right arrow. water
oxygen + water Right arrow. hydrogen + water
hydrogen + water Right arrow. oxygen
Answer: hydrogen + oxygen Right arrow .water
Explanation:
The exact equation for this reaction is;
2H2 + O2 -------------> 2H2O
hydrogen + oxygen Right arrow. water is the correct option.
The equation shows hydrogen reacting with oxygen to form water is as follows:-
[tex]2H_2+O_2\rightarrow2H_2O[/tex]
The above reaction in word form is written as follows:-
[tex]hydrogen+Oxygen \rightarrow water[/tex]
So, hydrogen + oxygen Right arrow. water is the correct option.
Hydrogen-H
Oxyden-O
Water-[tex]H_2O[/tex]
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How many moles of ammonium sulfate, (NH4)2SO4, can be made from the reaction of 30.0 mol of NH3?
Consider the reaction 2Na+ Cl2 - 2NaCl.
and is
Na is
Oxidized or reduced
Answer:
the other one is correct...
a. oxidized
b. reducing agent
Explanation:
edge 2021 just did it
The sodium in the given reaction is oxidized from Na to Na⁺.
What is oxidation?Oxidation can be described as a process that involves the addition of oxygen or an electronegative element or the removal of hydrogen atoms or any electropositive element. Oxidation can be defined as the reaction in which an atom or ion loses its electrons.
The reduction can be defined as a reaction that involves the addition of hydrogen or the removal of oxygen or any electronegative element. The reduction can also be defined as the reaction in which an atom or ion gains electrons.
In the given chemical reaction of the formation of NaCl:
[tex]2Na + Cl_2\longrightarrow 2NaCl[/tex]
In this chemical reaction the sodium is oxidized as shown below:
[tex]Na\longrightarrow Na^+ +e^-[/tex]
In this chemical reaction the Chlorine is reduced as shown below: [tex]Cl_2 +2e^-\longrightarrow 2Cl^-[/tex]
Therefore, sodium is oxidized in the given reaction.
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3.5 moles of argon gas are maintained at a temperature of 293K and a pressure of 2.5 atm. What is the volume
occupied by the argon gas sample? Value of R = 0.0821 L. atm/mol-K
A 33.7L
B 22.4L
C 31.2L
D 17.2L
Answer:
A 33.7L
Explanation:
Hello,
In this case, we can deal with argon as an ideal gas that can be studied via the ideal gas equation:
[tex]PV=nRT[/tex]
Whereas we have the pressure, volume, moles, ideal gas constant and temperature respectively, so, for us to find the volume we simply solve for it as shown below:
[tex]V=\frac{nRT}{P} =\frac{3.5mol*0.082\frac{atm*L}{mol*K} *293K}{2.5atm} \\\\V=33.7L[/tex]
Therefore, the answer is A 33.7L.
Best regards.
In the early twentieth century , what was alexander fleming's hypothesis concerning the relationship between a yellow green mold and certain strains of bacteria
Answer:
Explanation:
Alexander Fleming's hypothesis was that the juice that was produced by the mold that appeared in the petri dishes was killing the bacteria growing there (streptococcus, meningococcus and the diphtheria bacillus).
Answer:
He thought the mold had released a chemical that prevented the bacteria’s growth.
Explanation:
Gradpoint
Astronomers studying the planet of Rhombus have detected sedimentary rock on its surface. One astronomer wonders if material in this sedimentary rock used to be in igneous rock deep in Rhombus's interior. Can igneous rock become sedimentary rock? Explain your answer
Yes, igneous rock become sedimentary rock through a process called sedimentation.
The sedimentary rock formed in the process above arises from sediment that was compacted and cemented. When igneous rock is lifted up by plate motion toward Rhombus’s surface, it become exposed to energy from Rhombus’s sun. Therefore, wind and water can move and breakdown the igneous rock into sediment. This process here, the sedimentary rock could have been igneous rock.In sedimentation, An igneous rock is broken down or crushed into little piece of rock called sediment, the sediment is then packed together as a result of othe rocks or strong forces, that form together to make a Sedimentary rock.
Conclusively, The process of erosion, heat and depositing rock grains which can also be known as sedimentation can alter or change igneous rock into sedimentary rock.
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Can you help solve each question I answered incorrectly
Answer:
1.2cm
97.8mm
7cm