Answer:
Energy released = 18.985 J
Explanation:
The exponential decay of radioactive substance is given by -
N(t) = N₀ [tex]e^{-kt}[/tex]
where
N₀ = initial quantity
k = decay constant
Half life, [tex]t_{1/2} = \frac{ln 2}{k}[/tex]
⇒[tex]k = \frac{ln 2}{t_{1/2} }[/tex]
Given,
N₀ = 12.5 + 3 = 15.5 × 10⁻⁶ gm
[tex]t_{1/2}[/tex] = 32.6 + 18 = 50.6 × 10⁶ years
So,
[tex]k = \frac{ln 2}{50.6 * 10^{6} }[/tex] = 1.361 × 10⁻⁸ year⁻¹
Now,
N(1) = 15.5 × 10⁻⁶ [tex]e^{-1.361*10^{-8} *1}[/tex]
= 15.49999978904
Now,
Substance decayed = N₀ - N(t)
= 15.5 × 10⁻⁶ - 15.49999978904 × 10⁻⁶
= 21.095 × 10⁻¹⁷ kg
⇒Δm = 21.095 × 10⁻¹⁷ kg
So,
Energy released = Δmc²
= 21.095 × 10⁻¹⁷ × 3 ×10⁸ × 3 × 10⁸
= 189.855 ×10⁻¹
= 18.985 J
⇒Energy released = 18.985 J
Fires are classified into various classes and as such different types of portable fire extinguishers must be used. The theory behind portable fire extinguishers is that the fire can be extinguished by removing any or more of the following four elements:
Fuel, Heat, Oxygen, Chain Reaction.
Identify the extinguishing mechanism and the classe(s) of fires they are used to extinguish for the following types of fire extinguishers:
ABC Powder, Carbon dioxide, Foam, Water.
Answer:
Explanation:
ABC Powder: sprays a very fine chemical powder. This acts to blanket the fire and suffocate it. Class A, B, C fires
Carbon dioxide: extinguishes CO2. By doing so, it removes oxygen from the fire, effectively suffocating it of oxygen. Class B fires
Foam: spray a type of foam that expands when it hits the air and blankets the fire. This prevents the vapors from rising off the liquid to feed the fire, thus starving it of fuel. Class A and B
Water: releases microscopic water molecules that fight the fire on a variety of levels. the level of oxygen in the air is decreased, which helps to suffocate the fire. Class: most all
also, your fire classes:
Class A: freely burning, combustible solid materials such as wood or paper
Class B: flammable liquid or gas
Class C: energized electrical fire (energized electrical source serves as the ignitor of a class A or B fire – if electrical source is removed, it is no longer a class C fire)
Class D: metallic fire (titanium, zirconium, magnesium, sodium)
Class K: cooking fires – animal or vegetable oils or fats
Please could you help me with this question
(No links or spam)
Will give brainliest if correct
Answer:
first one pure
second one mixture..
What is the reducing agent in the following reaction?
2 Br−(aq) + H2O2(aq) + 2 H+(aq) → Br2(aq) + 2 H2O(l)
Answer:
the reducing agent is Bromine
The oxidation state of an element is calculated by subtracting and the total sum of oxidation states of all the individual atom (excluding the one that has to be calculated) from total charge on the molecule. Bromine is the reducing agent in the following reaction.
What is oxidation state?Oxidation state of an element is a number that is assigned to an element in a molecule that represents the number of electron gained or lost during the formation of that molecule or compound.
The ionic equation is given as
2 Br⁻(aq) + H[tex]_2[/tex]O[tex]_2[/tex](aq) + 2 H⁺(aq) → Br[tex]_2[/tex](aq) + 2 H[tex]_2[/tex]O(l)
The oxidation state of bromine on reactant side is -1 while on product side it is 0 so, oxidation state of bromine has increased by 1 so, bromine is oxidized. If it is oxidized that means it must have reduced someone. So, bromine is acting as a reducing agent.
Therefore, bromine is the reducing agent in the given reaction.
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45. What is the H ion concentration of an aqueous solution
in which the OH-ion concentration is 1 x 10-2 mole
per liter?
A) 1 X 10-14 M
C) 1 x 10-9M
B) 1 x 10-12 M
D) | 10-2M
Answer:
= 1 X 10⁻⁻¹²M
Explanation:
At 25°C & 1atm [H⁺][OH⁻] = 1 x 10⁻¹⁴ => [H⁺] = 1 X 10⁻¹⁴/[OH⁻] = 1 X 10⁻¹⁴/1 X 10⁻²
= 1 X 10⁻⁻¹²M
Which measurement occurs last when collecting data to determine the
percentage by mass of a solution?
mass percent = (mass of element in 1 mole of compound / mass of 1 mole of compound) x 100. The formula for a solution is:
mass percent = (grams of solute / grams of solute plus solvent) x 100. or.
mass percent = (grams of solute / grams of solution) x 100. The final answer is given as %.
Hope this helps!!
If a dog has a mass of 21.5 kg, what is its mass in the following units? Use scientific notation in all of your answers.
What is the dog’s mass in grams?
What is the dog’s mass in milligrams?
What is the dog’s mass in micrograms?
Explanation:
use the conversation in the image
Plz answer the first two questions and maybe the third. I will give brainliest.
Answer:
1. 24.45 moles
2. 437.90 grams
Bonus :
0.75 grams
Explanation:
Hope it was helpful ;)
Make a
prediction about how a lack
of resources in an ecosystem
might impact the levels of
organization.
Answer:
Limiting factors of an ecosystem include disease, severe climate and weather changes, predator-prey relationships, commercial development, environmental pollution and more. An excess or depletion of any one of these limiting factors can degrade and even destroy a habitat.
Explanation:
The limiting factor of an ecosystem involve disease, weather change, climate change, environment pollution and more. An excess or depletion of any of these factor can destroy over habitat.
What is Ecosystem?An ecosystem is define as a community or a group of living organisms that live together and are dependent on each other.
There are two main types of ecosystem.
Terrestrial ecosystem-Terrestrial ecosystem are land based ecosystem and interaction of biotic and abiotic component in the specific area.
Example- forest, grassland desert etc.
Aquatic ecosystem-Aquatic ecosystem are ecosystem formed by surrounding water bodies. They are dependent on each other and their environment .
Example- lake, pond, river etc.
Thus ecosystem and their limiting factor have great impact on the level of organization.
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Which overall chemical equation is obtained by combining these intermediate equations?
What is the name of the structure formed when fertilization occurs?
Answer:
zygote
Explanation:
I got this online
Answer:
ᘔYᘜOTᗴ:=> In human fertilization, a released ovum (a haploid secondary oocyte with replicate chromosome copies) and a haploid sperm cell (male gamete)—combine to form a single 2n diploid cell called the zygote.
ʰᵒᵖᵉ ⁱᵗ ʰᵉˡᵖˢ
[tex] \infty \infty [/tex]
what is a chemical bond?
how ate chemical bond different from each other?.
Which do you use to qualify matter?
A. Thermometer
B. Five senses
C. Balance
D. Tape measure
Answer:
c balance
Explanation:
if you weigh something, you prove it's there.
how many atoms is in 1 molacule of uranium?
Answer:
One mole of U238 ( 6.022 X 10^23 atoms) is 238 grams; one mole of U235 is 235 grams. The difference in molecular weight between a mole of U235 and U238 is 3 grams, the secret to enriching uranium.
Explanation:
A compound with an approximate molar mass of
65.0g/mol is made up of C, H and Cl. This same
Compound contains 55% of Cl by mass .lf 9g
of the compound contains 4.19 x 10²³ atoms,
determine the compound's:
a empirical formular and molecular formular
Name 3 ways you can keep our community healthy?
Answer:
1. Practice healthy habits with kids in your life. ...
2. Engage in your school's efforts to encourage healthy practices. ...
3. Learn more about the decisions local officials are making that impact your environment. ...
4. Give back healthy options to your community.
Explanation:
Why is the method of using a density bottle more accurate than the measuring cylinder
Answer:
While measuring relative density of liquids, two common method of measuring the volume are a measuring cylinder and a density bottle. Among these two method the density bottle gives more accurate measurement of the volume, resulting in more accurate determination of density or relative density
Answer:
While measuring relative density of liquids, two common method of measuring the volume are a measuring cylinder and a density bottle. Among these two method the density bottle gives more accurate measurement of the volume, resulting in more accurate determination of density or relative density.
Explanation:
a solution of KCl in water has a concentration of 0.243 M. The solution has a volume of 0.580 L. How many grams of KCl are present in the solution?
Answer:
10.5 g
Explanation:
Step 1: Given data
Molar concentration of the solution (C): 0.243 MVolume of solution (V): 0.580 LStep 2: Calculate the moles of solute (n)
Molarity is equal to the moles of solute divided by the liters of solution.
M = n/V
n = M × V
n = 0.243 mol/L × 0.580 L = 0.141 mol
Step 3: Calculate the mass corresponding to 0.141 moles of KCl
The molar mass of KCl is 74.55 g/mol.
0.141 mol × 74.55 g/mol = 10.5 g
1. When there is light, photosynthesis can
A. occur, in the chloroplast.
B. not occur, and the stomata will not be open.
C. not occur, and the stomata will be open.
D. occur, in the
mitochondria.
Answer:
A
Explanation:
Answer:
A. occur, in the chloroplast.
Explanation:
Photosynthesis occur in chloroplasts, with the help of sunlight. Where mitochondria help in respiration
Help asap pls! Circulating air caused when warm air rises and cool air sinks. Convection currents occur throughout the world.
1.barrage 2.collection area 3.convection current
3. Convection Current
But just a tip Next time try to emphasize the question a little more ! Hope this helps :)
Metals are cunductor of heat and electricity prove this statement
Answer:Metals are an excellent conductor of electricity and heat because the atoms in the metals form a matrix through which outer electrons can move freely. Instead of orbiting their respective atoms, they form a sea of electrons that surround the positive nuclei of the interacting metal ions.
Explanation:
Five identical test tubes are each filled from the following five copper (11) sulfate stock solutions. Which of the following test tubes would appear the lightest blue?
a) Stock solution made form 0.200 moles of CuSO4 dissolved to a total volume of 400 ml
b) Stock solution made form 0.150 moles of CuSO4 dissolved to a total volume of 300 mL
C)Stock solution made form 0.250 moles of CuSO4 dissolved to a total volume of 500 ml
d) Stock solution made form 0.175 moles of CuSO4 dissolved to a total volume of 400 ml
e) Stock solution made form 0.125 moles of CuSO4 dissolved to a total volume of 300 ml
Answer:
deez cutz
Explanation:
did i get it right
what type of chart is used to help organize study and predict genetic inheritance?
Answer:
Its a punnet square
Explanation:
how many moles are there in 2.20 x 10^23 molecules of Na2SO4
Answer:
Explanation:
450 grams of Na2SO4? 450 Na soullnol Na2SO4 16.02x1023 molec, Na₂SO4 = 119x1024. | 142.05g Na25041 Imol Naz
75.0 grams of MgCl, is dissolved in 500.0 g of water, density 1.00 g/ml. What is the MOLALITY of this solution?
es -)
A)
0.50 m
B)
1.00 m
C)
1.58 m
D)
2.02 m
Answer:
C
Explanation:
Check it. So u can know it
Convert 25.4 grams of barium phosphate, Ba3(PO4)2 to formula units.
Both propanoic acid and propanone are soluble in water. Please draw a diagram and explain which compound is more soluble.
Answer:
Explanation:
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Answer:
dfgh
Explanation:
a wave machine creates ripples of water. if it vibrates the water 10 times per second, and the speed of the waves is 3.0 m/s, what is the wavelength?
Explanation is in a file
bit.[tex]^{}[/tex]ly/3a8Nt8n
Muscles and bones work together when muscles move bones through contracting and
relaxing.
A.true
B.false
I think it's true.
Explanation:
Muscles move bones through contracting and relaxing
How many moles of NaCl are contained in 50.0 mL of 2.50 M NaCl?
Answer: 0.144 moles. :)
Explanation:
The number of moles of NaCl that are contained in 50.0 mL of 2.50 M NaCl is 0.125 moles
Using this formula
Molarity=Moles of solute/Liters of solution
First step is to convert 50.0 mL to Liters
Litres=50.0 ml×1 L/1000 ml
Litres=0.05 L
Now let determie the number of moles of NaCl
2.50M=moles/0.05
moles=2.50M(0.05)
moles = 0.125 moles of NaCl
Inconclusion The number of moles of NaCl that are contained in 50.0 mL of 2.50 M NaCl is 0.125 moles
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