Strontium-90 is one of the products of the fission of uranium-235. This strontium isotope is radioactive, with a half-life of 28.1 yr. Calculate how long it will take for 0.900 g of the isotope to be reduced to 0.170 g by decay.
Answer:
67.6 years is the time the isotope take to decay from 0.900g to 0.170g
Explanation:
The radioactive decay follows first order law:
Ln [A] = -kt + ln[A]₀
Where [A] is concentration after time t,
k is decay constant:
k = ln 2 / t(1/2)
k = ln2 / 28.1 years
k = 0.02467 years⁻¹
[A]₀ = Initial concentration.
We can replace concentration and use the mass of the isotope:
Ln [A] = -kt + ln[A]₀
Ln [0.170g] = -0.02467 years⁻¹t + ln[0.900g]
-1.667 = -0.02467 years⁻¹t
t =
67.6 years is the time the isotope take to decay from 0.900g to 0.170gThe time required for the sample to reduce to 0.170 grams has been 67.75 years.
Half-life can be defined as the times required by the substance to reduce to half of its initial concentration.
The half-life can be expressed as:
Amount left = Initial amount [tex]\times[/tex] [tex]\rm \dfrac{1}{2}^\dfrac{time}{Half-life}[/tex]
From the given:
0.17 g = 0.9 [tex]\rm \times\;\dfrac{1}{2}^\dfrac{t}{28.1}[/tex]
[tex]\rm \dfrac{0.17}{0.9}[/tex] = [tex]\rm \dfrac{1}{2}^\dfrac{t}{28.1}[/tex]
0.188 = [tex]\rm (0.5)^\dfrac{t}{28.1}[/tex]
Taking log on both the sides,
log 0.188 = [tex]\rm \dfrac{t}{28.1}\;\times[/tex] log 0.5
2.411 = [tex]\rm\dfrac{t}{28.1}[/tex]
t = 2.411 [tex]\times[/tex] 28.1 years
Time = 67.75 years.
The time required for the sample to reduce to 0.170 grams has been 67.75 years.
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What is the definition of a community in environmental science
Volcanic island acres are associated with which type of plate boundary
Where is type of precipitation is most likely to form during a thunderstorm
Answer:
hail, btw have a nice day
Answer:
Hail
Explanation:
I got it right on my test
What affects wind speed?
Answer:
At the Earth's surface, wind blows horizontally from high pressure to low pressure areas. The speed is determined by the rate of air pressure change, or gradient, between the two pressure areas. The greater the pressure difference, the faster the winds.
- sciencing
The Four Forces That Influence Wind Speed & Wind Direction
Explanation:
what element has an electron configuration of 2-1:
Answer:
Lithium
Explanation:
The element with electronic configuration of 2, 1 is helium.
In the electronic configuration, we are able to know that the total number of electrons the atom contains is 3. Also, the element has one electron in the outer most shell.
Elements with one valence electrons are the alkali metals.
Therefore, this configuration clearly matches Lithium.
What is the independent variable when testing to see how the viscosity of a liquid affects its flow rate
Answer:
Viscosity
Explanation:
The viscosity of the liquid is the independent variable. The flow rate is the dependent variable in this hypothesis.
The statement given is called the hypothesis. It is a form of scientific guess into a phenomenon.
An independent variable is the cause. A dependent variable is the effect produced. In this hypothesis, the cause of the various flow rate of the liquid is the viscosity. It is therefore the independent variable. The flow rate is the dependent variable.7. Aluminum, iron, copper, and oxygen are all examples of which of the following?
Answer:
Explanation:
Elements
Which one will diffuse faster Ammonia or carbon dioxide Why?
jcp-fnoa-kzk join here
what is the volume of 5 moles of oxygen gas at rtp
Answer:
5 moles of oxygen occupy 120 dm³ volume.
Explanation:
Given data:
Number of moles = 5 mol
Volume of gas = ?
Solution:
In question it is given gas is at room temperature and pressure.
One mole of any gas at room room temperature and pressure occupy volume of 24 dm³. Thus,
5 mole of gas occupy volume of,
5 mol × 24 dm³/1 mol
120 dm³
5 moles of oxygen occupy 120 dm³ volume.
The density of ice at its freezing point is 0.917 g/cm3. What is the mass of 2.5 cm3 of ice at this temperature?
A. 1.6 g
B. 2.3 g
C.2.7 g
D.3.4 g
Answer:
The answer is option BExplanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volume
From the question we have
mass = 0.917 × 2.5 = 2.2925
We have the final answer as
2.3 gHope this helps you
Answer:. 2.3 g
Explanation:
Explain how the forces involved in a car crash could lead to multiple cars coming to a complete stop. Use information from the article in order to answer this question. You should be answering in at least 2 complete sentences.
Answer:
Newton's First Law...
Explanation:
The only force that acts on the car is the sudden deceleration from v to 0 velocity in a brief period of time, due to the collision with another object. However, when viewing the total system, the collision in the situation with two cars releases twice as much energy as the collision with a wall
Which of the following claims about a binary compound composed of elements with the same electronegativity is most likely to be true?
A
Tully compound has properties similar to those of both elements.
The bonding in the compound is nonpolar covalent.
с
The boiling point of the compound is above 1000°C.
D
The compound contains strong ionic bonds.
I think it's D
Hope that helps
Answer: B, the bonding in the compound is nonpolar covalent.
Explanation:
This is because with the same electronegativity, there is an equal sharing of electrons, which indicates that the bonding must be nonpolar.
How do desalination plants work?
Answer:
Hope this will help..........
Explanation:
Seawater desalination is the removal of salt and impurities from seawater to produce fresh water. Our desalination plants use a reverse osmosis process. ... The filtered seawater is then forced under pressure through special membranes whereby the osmosis process that normally occurs in nature is reversed
A reddish layer of rust can form on old iron nails and bikes. In this chemical reaction, iron reacts slowly with oxygen in the air. The chemical name for rust is iron oxide. What are the reactant(s) and product(s) of this reaction? Write down the equation, in words, for the formation of rust.
Answer:
Iron slowly reacts with oxygen and forms rust. In this case, the reactants are iron and oxygen. The product is rust, or iron oxide. The chemical equation looks like this:
Explanation:
iron + oxygen → iron oxide
Answer:
Iron slowly reacts with oxygen and forms rust. In this case, the reactants are iron and oxygen. The product is rust, or iron oxide. The chemical equation looks like this:
iron + oxygen → iron oxide
Explanation:
This was the answer straight from Plato. I hope that this helped you, please mark me the brainiest, like and rate my answer if it did! :)
What happens when the atoms of a substance are regrouped
Atoms of a given elements with have the same mass true or false?
Answer: True
Explanation:
When mixing an acid with water, which of the following must always be done?
A.
Never mix an acid with water, it will explode.
B.
Always add the acid to the water slowly, taking a moment to stir between drops.
C.
Always heat the acid before mixing with water.
D.
Always shake both solutions before mixing.
Answer:
B
Explanation:
Answer:
B. Always add the acid to the water slowly, taking a moment to stir between drops
Whats faster light or sound? PLEASE HELPY ME
Answer:
The answer is that light is faster than sound.
Explanation:
A good example is of lightning and thunder during a thunderstorm.
mark me brainliest!
When the following equation is balanced, the coefficients are __________. Al(NO3)3 + Na2S → Al2S3 + Na(NO3)
The balanced coefficients in the reaction are now; 2, 3, 1, 3.
A balanced chemical reaction equation is one in which the number of atoms of each element on the right hand side of the reaction equation is equal to the number of atoms of the same element on the left hand side of the reaction equation.
For the reaction show, the balanced reaction equation is; 2Al(NO3)3 + 3Na2S → Al2S3 +3 Na(NO3). The balanced coefficients in the reaction are now; 2, 3, 1, 3.
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ANSWER THIS TO BE MARKED BRAINILEST Water in a beaker measures 250 milliliters. A rock is completely submerged in the water. The water level now reads 375 milliliters. What is the volume of the rock in cubic centimeters? Explain your answer
Answer:
125 cubic meters
Explanation:
Subtract 375-250=125 cubic meters
Question 2 (1 point) The chemical formula for an ionic compound represents the a b number of ions in each molecule. total number of ions in the crystal lattice. number of atoms in each molecule simplest ratio of ions that results in an electrically neutral compound.
The chemical formula for an ionic compound represents the simplest ratio of ions that results in an electrically neutral compound. That is option D.
What is an ionic chemical compound?An ionic chemical compound is defined as the type of chemical compound that contains both the oppositely-charged ions of a metal and a nonmetal are attracted reacting with each other to form an ionic bond.
When represented as a chemical formula, it is the simplest ratio of ions that results in an electrically neutral compound.
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A student used the Dumas method to determine the molar mass of a volatile material. They placed the container into the ice bath BEFORE all of the material was vaporized. What will happen to their final calculations?
A. The Molar Mass will be too low.
B. The Molar Mass will not be effected.
C. The Molar Mass will be too high.
Answer: the molar mass will be too high
Explanation:
When an object resist movement by a force
Answer: Inertia
Explanation:
What element has the following electron configuration? 1s 22s 22p 63s 23p 64s 2
Answer:
answer is D
Explanation:
Uranium-235 undergoes the following fission process after
absorbing a neutron:
235 U +in+Kr + 14 Ba + xon
What is the value of x?
x =
Your answer should be a number.
The value of x = 3
Further explanationFusion and fission reactions are reactions involving atomic nucleus reactions
Fission reaction is a nucleation division reaction by firing a particle usually neutron so that it gets smaller particles of atomic nuclei.
Fission of Uranium-235
[tex]\tt ^1_0n+^{235}_{92}U\rightarrow ^{141}_{56}Ba+^{92}_{36}Kr+3^1_0n[/tex]
In this reaction, the sum of the mass number and atomic number of the elements involved in the reaction will be equal
atomic number left : 0+92=92
atomic number right : 56+36=92
mass number left : 1+235=236
mass number right : 141+92+3=236
The value of x in the fission process of uranium has been 3.
Fission reaction has been the nuclear reaction resulting in the breaking of the element into smaller substituents. The fission of uranium has been:
n + U [tex]\rightarrow[/tex] Ba + Kr + n
In the given fission reaction, the mass number of the atoms on the right and left of the reaction has to be equal. The mass number has been;
235 + 1 = 141 + 92 + x
236 = 233 + x
x = 236 -233
x = 3
The value of x in the fission process of uranium has been 3.
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Identify ALL the possible mol ratio from
this balanced equation:
Answer:
[tex]\frac{1 mole of N_{2} }{3 moles of H_{2} }[/tex]
Explanation:
The equation of the reaction:
Nitrogen gas N₂ reacts with Hydrogen as H₂ to produce ammonia NH₃;
N₂ + H₂ → NH₃
The balanced equation is ;
N₂ + 3H₂ → 2NH₃
The mole ratio is the ratio of the coefficients of the combining reactants;
1 mole of N₂ combines with 3 mole of H₂;
So;
[tex]\frac{1 mole of N_{2} }{3 moles of H_{2} }[/tex]
A neutral atom of gold has the same number of electrons and what?
Why do we dream? Help me Please;)
Answer:
Explanation:
we dream because when our bodies are taking memories into long term, the memories from that day or the day before collide and make dreams. that is why they resemble things that have happened to us.
Answer:
One widely held theory about the purpose of dreams is that they help you store important memories and things you've learned, get rid of unimportant memories, and sort through complicated thoughts and feelings. Research shows that sleep helps store memories.
The brain is so active when we dream that it is virtually indistinguishable from a brain in the waking state. Even so, the chemistry of it is entirely rewired when we sleep. Many scientists attribute this to the reason dreams are so strange and bizarre.
Explanation:
Marissa blows up balloons for a party. She decides how big or small to make each balloon. Why does the air she blows into each balloon take up all the space inside the balloon