A sample of radioactive waste has a half-live of 40 years and an activity level of 4 curies. After how many years will the activity level of this sample be 0. 5 curies?
After 160 years, the activity level of the sample will be 0.5 curies.
What is half-life?Half life of any radioactive waste is the half decay of that product.
The formula is [tex]\dfrac{\lambda }{\lambda_1} = 2^\dfrac{a}{b}[/tex]
Where, λ is 4 cruies
λ1 is 0.5 cruies
b = 40 years
Putting the values in the equation
[tex]\dfrac{4}{0.5} = 2^\dfrac{a}{40}\\\\\\\dfrac{a}{40} = 4\\ = 160 years[/tex]
Thus, the correct option is 160 years.
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What is the change in the freezing point of water when 35.0 g of sucrose is
dissolved in 300.0 g of water?
Kf of water = -1.86°C/mol
molar mass sucrose = 342.30 g/mol
ivalue of sugar = 1
A. -0.183°C
B. 0.0606 °C
C. 0.217°C
D. -0.634°C
From the calculations, we can see that, the change in the freezing point is -0.634°C.
What is freezing point?The term freezing point refers to the temperature at which a liquid is changed to solid.
Given that;
ΔT = K m i
Number of moles sucrose = 35.0 g/ 342.30 g/mol = 0.1 moles
molality = 0.1 moles/ 300.0 * 10^-3 Kg
= 0.33 m
Thus;
ΔT = -1.86°C/mol * 0.33 m * 1
= -0.634°C
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Question 2
1 p
White phosphorus ignites easily. This is an example of _____ property
- physical
- neither
- chemical
- both
Answer:
Chemical properties because if it was physical property then it will glow in dark
What do esters aldehydes and ketones all have in common? (Look back at
table R and be specific!)
what is the wavelength of an electromagnetic wave that has a frequency of
1.82 x 1018 hz in a vacuum? (the speed of light in a vacuum is 3.00 x 108
m/s.)
The wavelength of an electromagnetic wave that has a frequency of 1.82 x 10¹⁸ Hz in a vacuum is 1.65 × [tex]10^{-10}[/tex]m.
How to calculate wavelength?The wavelength of a wave can be calculated by dividing the speed of the wave by its frequency.
According to this question, a wave has a frequency of 1.82 x 10¹⁸ Hz in a vacuum and speed of light in a vacuum is 3.00 × 10⁸ m/s.
λ = [tex]\frac{v}{f}[/tex]
Wavelength (λ) = 3 × 10⁸ ÷ 1.82 × 10¹⁸
Wavelength (λ) = 1.65 × [tex]10^{-10}[/tex] m
Therefore, the wavelength of an electromagnetic wave that has a frequency of 1.82 x 10¹⁸ Hz in a vacuum is 1.65 × [tex]10^{-10}[/tex]m.
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Match the following terms:
Answer:
See below ~
Explanation:
A to B
⇒ Solid Phase
==========================================================
B to C
⇒ Melting
==========================================================
C to D
⇒ Liquid Phase
==========================================================
D to E
⇒ Vaporizing
============================================================
E to F and beyond
⇒ Gas Phase
What is a chemical property? Give an example.
Answer:
A chemical property example is fire.
Explanation:
Hope this helps!
Are these structure form a week bases?
Answer:
Explanation:
I have only answered the blue boxed parts:
Amines are weak bases because they can accept protons from other things.
Sugars is neither acidic nor basic (cuz its not ionic)
Carboxylic acid are weak acids (not bases) cuz they donate protons to other things.
Fatty acids can be ____________ , meaning they contain double bonds, or they can be ____________ , meaning they contain no double bonds
Engineers are trying to improve a race car. Their goal is to increase the acceleration of the car using the same engine. Which change shows the best application of Newton’s laws of motion to achieve this goal?
increasing the inertia of the car
decreasing the reaction force
increasing the action force
decreasing the mass of the car
If the engineers are trying to increase the acceleration of the car, they have to decrease the mass of the car.
What is Newtons law?The Newtons laws of motion form the basis of the discussion about motion. We know that from the second law of Newton F = ma
Thus, if the engineers are trying to increase the acceleration of the car, they have to decrease the mass of the car.
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Scientists made the following two observations about emission spectra: each element has a unique emission spectrum. atoms emit energy only at specific wavelengths. describe how the bohr model explains both of these observations.
In this model, electrons are found on unique levels and when jumping from one level to another, electrons emit light at a specific wavelength.
What is the Bohr model?The Bohr model is an atomic model describing the properties of atoms and their constituents (electrons).
This model states different atoms have specific levels of energy where electrons can be located.
In conclusion, in this model, electrons are found on unique levels and when jumping from one level to another, electrons emit light at a specific wavelength.
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Answer:
In the Bohr model, electrons can exist only in certain energy levels surrounding the atom. The energy levels in each atom are unique. When electrons jump from a higher energy level to a lower one, they emit light at a wavelength that corresponds to the energy difference between the levels.
Explanation:
Ed22
Based on table n, uranium-238 and uranium-235 have different
a)decay modes
b)half lives
c)number of protons
d)number of electrons
According to table N, the isotopes uranium-238 and uranium-235 have different half lives.
What are radioactive nuclides?Radioactive nuclides are those nuclides that are able to undergo radioactive decay. They have specific modes of decay that is peculiar to each isotope.
Hence, according to table N, the isotopes uranium-238 and uranium-235 have different half lives.
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Based on the activity series provided, which reactants will form products? f > cl > br > i cui2 br2 right arrow. cl2 alf3 right arrow. br2 nacl right arrow. cuf2 i2
The reactants that will form products will be [tex]2CuI_2 + Br2[/tex].
Activity seriesElements at higher positions in the activity series will be able to displace those in lower positions in solutions.
Thus:
[tex]2CuI_2 + Br2 --- > 2CuBr +2 I_2[/tex] because Br is higher than I in the activity series.
Cl cannot displace F in [tex]Cl2 + AlF_3[/tex] because F is higher than Cl in the activity series.
Also, Cl is higher than Br in the activity series, thus, the reaction [tex]Br_2 + NaCl[/tex] cannot form products.
I cannot displace F, thus, [tex]CuF_2 + I_2[/tex] cannot form products.
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Hereditary information is stored inside the
Answer:Hereditary information is contained in genes, located in the chromosomes of each cell. Each gene carries a single unit of information. An inherited trait of an individual can be determined by one or many genes, and a single gene can influence more than one trait.
Explanation:
Can someone help??. This is super hard
111 cchuyttrfgh
tyujklkjhgt
What is the name of cuo? explain how you determined the bond type and the steps you used to determine the naming convention for the compound.
The name of CuO is Copper(II) oxide have the two most common oxidation states of copper are +2 and +1.
What is copper oxide used for?Copper oxide is a trace element for the zootechnical and agricultural sector. Cupric oxide is also used as a raw material for the production of catalysts and pigments in the field of ceramics, glass and plastics.
This compound makes two different types of bonds being the hydrogen bond when it's a hydrogen and covalent bond when we have an oxygen or a nitrogen.
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What kind of scientist would study how mistletoe harms trees
Answer:
A Dendrologist! They are the type of Scientist that studie trees.
Compare and contrast nuetrons,protons, and electrons
283.5 g of tin was heated from 25.6 to 107.5°C. How much energy was used to heat tin? (Specific heat capacity of Sn is 0.222 J/g x °C)
Answer: 5150 J
Explanation:
[tex]Q=mc \Delta T\\\\Q=(283.5)(0.222)(107.5-25.6)\\\\Q \approx \boxed{5150 \text{ J}}[/tex]
Consider a 1.0-L sample of helium gas and a 1.0-L sample of argon gas, both at room temperature and atmospheric pressure. Do the atoms in the helium sample have the same average kinetic energy as the atoms in the argon sample
Yes, the atoms in the helium sample have the same average kinetic energy as the atoms in the argon sample.
What is Average Kinetic Energy ?The average kinetic energy of a gas molecule is defined as the product of half of the mass of each gas molecule and the square of the RMS speed.
The average kinetic energy equation is independent of Molar mass.
It's only a function of temperature.
So if they're at the same temperature they will have the same average kinetic energy.
Therefore, the atoms in the helium sample have the same average kinetic energy as the atoms in the argon sample
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Is Hibiscus tea good for ACNE?
Answer:
Y E S
Explanation:
Hibiscus tea has plenty of skin care qualities, from helping your natural levels of collagen and elastin to reducing breakouts to balancing oil production. Hibiscus is known for its rich level of antioxidants, including vitamin C and beta-carotene.
I hope this helps ✍(◔◡◔)
list three properties of water that are related to hydrogen bonding
If the half-life of a radioactive group of atoms is 100 years, then how old is the rock if there have been two half-lives? show your work
The rock will be 200 years old if there have been two half-lives.
What is the half life ?The half-life of a radioactive isotope refers to its decay period, which is the average lifetime of an atom before it disintegrates.
In this question (t½) of rock is 100 years, which means that after 100 years half of the sample would have decayed and half would be left as it is.
after two half lives or 200 years , the rock will be 200 years old.
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Use the following equation to answer the following question
3 H2 + Na2 —-> 2 NH3
a) Determine the limiting reactant when 5.78 g of H2, and 6.28 g N2 are reacted to make NH3 you expect to get out of the chemical reaction.
Answer: nitrogen
Explanation:
Converting 5.78 g of hydrogen to moles, we know that the formula mass of hydrogen is about 2(1.00794)=2.01588 g/mol, so 5.78 grams is about 5.78/2.01588=2.867 mol.Converting 6.28 g of nitrogen to moles, we know that the formula mass of nitrogen is about 2(14.0067)=28.0134 g/mol, so 6.28 grams is about 6.28/28.0134 = 0.22417 mol.From the equation, we know that for every 3 moles of hydrogen consumed, 1 mole of nitrogen is consumed.
Considering the hydrogen, the reaction can occur 2.867/3=0.955 times.Considering the nitrogen, the reaction can occur 0.22417 times.Therefore, nitrogen is the limiting reactant.
Match the phase to the correct definition.
1.
Anaphase
2.
Prophase
3.
Metaphase
4.
Telophase
a.
Chromosomes line up at the center of the cell.
b.
The DNA is organized into connected rods called chromosomes.
c.
New cells begin to form.
d.
The chromosomes are separated and move to opposite sides of the cell.
Answer:
1.) Anaphase ------> D.) The chromosomes are separated and move to opposite sides of the cell.
2.) Prophase -------> B.) The DNA is organized into connected rods called chromosomes.
3.) Metaphase -------> A.) Chromosomes line up at the center of the cell.
4.) Telophase ------> C.) New cells begin to form.
which of the following with the kinetic theory address? a
A. Vibrations in molecules
B. Oxidation states of Adams
C. Shapes of molecules
D. Energy levels and electrons
Answer:A
Explanation:
The kinetic molecular theory of matter states that: Matter is made up of particles that are constantly moving. All particles have energy, but the energy varies depending on the temperature the sample of matter is in.This is turn determines shearer the substance exists in the solid, liquid, or gaseous state.
What volume of a 0.295 M nitric acid solution is required to neutralize 24.8 mL of a 0.107 M potassium hydroxide solution
Answer: 9.00 mL
Explanation:
[tex]M_{A}V_{A}=M_{B}V_{B}\\(0.295)V_{A}=(0.107)(24.8)\\V_{A}=\frac{(0.107)(24.8)}{(0.295)} \approx \boxed{9.00 \text{ mL}}[/tex]
In a mixture of oxygen and nitrogen, 80% of the gas pressure is exerted by the nitrogen. if the total pressure is 2.0 atm, what pressure does the oxygen exert?
0.4 atm pressure exerted by oxygen if 80% of the gas pressure is exerted by the nitrogen.
What is pressure?Pressure is defined to be the amount of force exerted per area
80% of pressure is exerted by nitrogen gas.
So, 20% of pressure will be exerted by oxygen gas.
20% of 2.0 atm = 0.4 atm
Hence, 0.4 atm pressure exerted by oxygen if 80% of the gas pressure is exerted by the nitrogen.
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Calculate the molarity of a Ba(OH)2 solution if 1950 mL is completely titrated by 26.1 mL of 0.505 M HNO3
Answer: 0.01 M
Explanation:
[tex]M_{A}V_{A}=M_{B}V_{B}\\(26.1)(0.505)=(1950)M_{B}\\M_{B}=\frac{(26.1)(0.505)}{1950} \approx \boxed{0.01 \text{ M}}[/tex]
Could someone explain this for me I don't understand?
Answer:
Ok so I assume they gave u a reaction before asking this question. Look at that reaction and try to figure out what substances are changing in valency, if there is a substance(s) that doesn't change its valency then it's a spectator ion.