Answer: The half life of the sample of silver-112 is 3.303 hours.
Explanation:
All radioactive decay processes undergoes first order reaction.
To calculate the rate constant for first order reaction, we use the integrated rate law equation for first order, which is:
[tex]k=\frac{2.303}{t}\log \frac{[A_o]}{[A]}[/tex]
where,
k = rate constant = ?
t = time taken = 1.52 hrs
[tex][A_o][/tex] = Initial concentration of reactant = 100 g
[A] = Concentration of reactant left after time 't' = [100 - 27.3] = 72.7 g
Putting values in above equation, we get:
[tex]k=\frac{2.303}{1.52hrs}\log \frac{100}{72.7}\\\\k= 0.2098hr^{-1}[/tex]
To calculate the half life period of first order reaction, we use the equation:
[tex]t_{1/2}=\frac{0.693}{k}[/tex]
where,
[tex]t_{1/2}[/tex] = half life period of first order reaction = ?
k = rate constant = [tex]0.2098hr^{-1}[/tex]
Putting values in above equation, we get:
[tex]t_{1/2}=\frac{0.693}{0.2098hr^{-1}}\\\\t_{1/2}=3.303hrs[/tex]
Hence, the half life of the sample of silver-112 is 3.303 hours.
Which reaction takes place in a nuclear fission reactor?
C+HN
2 Put He → Cm
OCO+ He-Cot 'n
o U+ nKr+Ba+3'n
Answer:
The reaction that takes place in a nuclear fission reactor is answer D.
Explanation:
Step-by-step explanation:
Nuclear fission reactions involves the process by which large atomic nuclei are bombarded with energetic particles and release of an enormous amount of nuclear energy, which mainly ends up as heat energy.
So now, consider the nuclear reaction from D, after the uranium nucleus absorbs the neutron its split into two smaller nuclei (often radioactive themselves), Krypton and Barium and releases more neutrons (or energy).
A student makes observations of a tree in a nearby forest. Which of the following observations of the
tree's characteristics would be useful in determining its identity with a dichotomous key?
A
It contains the nests of several birds.
B
Its leaves are long and narrow.
с
Its branches were recently cut.
D
It provides shade for ground brush.
The observations of the tree's characteristics would be useful in determining its identity with a dichotomous key is its leaves are long and narrow. The correct option is B.
What is an observation?Observation is a process of recognizing and recording an event or fact that frequently involves measuring it with tools. Recognizing and recording an event, or fact frequently involves measuring with tools. Field notes are written observations made while participating in field observations or immediately afterward.
They are crucial for understanding phenomena that have been seen in the field. Field notes frequently take the form of scratch notes, diaries, and notebooks. In the scientific field, observation is a crucial step.
Therefore, the correct option is B. Its leaves are long and narrow.
To learn more about observation, refer to the link:
https://brainly.com/question/13196625
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Answer:
bottom right corner with arrows going up
Justin is making a snack. He toasts a piece of bread and first peanut butter and jelly on it. Then he cut an apple into several slices and adds these to his plate. Next Justin mixes a scoop of lemonade powder into a glass of water mixes it in Dad's ice. How many chemical changes occurred in this scenario? 1 2 three or four
Answer:
2
Explanation:
Toasting bread and lemonade powder in water are chemical changes. Pb&j on bread and cutting apple are physical changes.
Answer:
b
Explanation:
What is electron affinity?
Answer:
The ability of an atom to accept an electron.
Explanation:
Electron affinity is measured by observing the energy change of a substance when an electron is added to it in its neutral gas form. For example, elements that are on the far right of the periodic table (excluding noble gases) are more likely to accept electrons rather than give them up. This is why Fluorine has the highest electron affinity of all atoms on the periodic table.
What is the degree of oxidation of a simple substance
Answer:
The oxidation state of a free element (uncombined element) is zero. For a simple (monoatomic) ion, the oxidation state is equal to the net charge on the ion. For example, Cl– has an oxidation state of -1. When present in most compounds, hydrogen has an oxidation state of +1 and oxygen an oxidation state of -2
What is the electron configuration for N (nitrogen)?
A. 1s22s23s23p1
B. 1s21p5
C. 1s22s22p3
D. 1s22s22p23s1
Explanation:
₇N = 1s² 2s² 2p³
Group = 15period = 2atomic mass = 14Hydride of Nitrogen = Ammoniavalency = 3Therefore,
Option C is correct ✔
8)
C(diamond) → C(graphite)
delta G° = -2.9 kJ/molrxn
Which of the following best explains why the reaction represented above is not observed to occur at
room temperature?
(A) The rate of the reaction is extremely slow because of the relatively small value of AGº for
the reaction.
(B) The entropy of the system decreases because the carbon atoms in graphite are less ordered
than those in diamond.
(C) The reaction has an extremely large activation energy due to strong three-dimensional
bonding among carbon atoms in diamond.
(D) The reaction does not occur because it is not thermodynamically favorable.
Answer: its b hope this helps.
Explanation:
Which of the following statements is true?
Electrons have a positive charge.
Protons and neutrons are found in the nucleus.
Electrons and protons are found in the nucleus.
All shells can hold up to eight electrons.
Answer:
2/ Protons and neutrons are found in the nucleus.
Explanation:
What do you have to do to break a molecule?
Answer:
Heat the molecule
Explanation:
Since most bonds require energy to form, they also give off energy when they are broken. But before most bonds break, the molecule has to be heated. Then the atoms start to move, and when they move too much, the bond breaks. Molecules that require less energy to break than they give off when broken are called fuels.
A compound is an example of pure substance
True
False
What is required to cause change in matter
Answer:
Adding or removing energy from matter causes a physical change as matter moves from one state to another. For example, adding thermal energy (heat) to liquid water causes it to become steam or vapor (a gas). And removing energy from liquid water causes it to become ice (a solid). ... Most liquids contract as they freeze.
Explanation:
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When chemists work with solid materials, we simply weigh out amounts of solid reagents and calculate mole amounts when thinking about stoichiometry. However, when we dissolve a solid (also known as a solute) in a solvent to form a solution, the solute becomes evenly distributed throughout the solution and we need to know how many moles of solute are present in a particular volume of solution.a) A solution is created by dissolving 13.5 grams of ammonium chloride in enough water to make 315 mL of solution. How many moles of ammonium chloride are present in the resulting solution?b) What is the molarity of the solution described above?c) To carry out a particular reaction, you determine that you need 0.0500 moles of ammonium chloride. What volume (mL) of the solution described above will you need to complete the reaction without any leftover NH4Cl?
Answer:
See the answers below
Explanation:
13.5 g of NH4Cl was dissolved in 315 mL of water.
Moles of NH4Cl present in the solution = mass/molar mass
Molar mass of NH4Cl = 54.49 g/mol
a) Moles of NH4Cl = 13.5/54.49
= 0.25 mole
b) Molarity of solution = moles of solute/volume of solution
moles of NH4Cl = 0.25
volume of solution = 315 mL = 0.315 L
molarity = 0.25/0.315
= 0.79 M
c) moles required = 0.0500 mole
molarity = 0.79 M
molarity = moles x volume
volume = molarity/moles
= 0.79/0.0500
= 15.8 L = 15,800 mL
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Answer:
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Explanation:
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 Right arrow.
Answer: Cul2 + Br2 ->
Explanation:
Answer:
i believe the answer is a
Explanation:
Argon (Ar) is an element in group 18. Argon is _____.
a gas highly reactive
a metalloid
a good conductor of heat
Answer:
c
Explanation:c
it is a good conducter
4. Look at the equation below and determine what fitsI in the empty box.
14 C --> 4 N+
?
re
c. en TH
What belongs in the empty box?
A.
В.
e
D.
Answer:
Beta particles
Explanation:
A beta emission is said to occur when a neutron is converted into a proton. When a beta emission takes place, the daughter nucleus increases it's atomic number by 1. A neutrino is also produced.
Since the mass number remain the same but the daughter nucleus has it's atomic number increased by 1, then the particle is a beta particle.
Explain how atoms organize to create larger structures?
Answer:
First of all they are super tiny particles of neutrons, electrons and protons. Then they come together to organize a structure of atom. Atoms come together to form a molecule and smaller molecules work together to form macromolecules. Thus, how they organize and form building blocks of a substance.
Hope it helps!<3
The red outlined elements have what major characteristics in common?
1 point
Metals, Nonmetals, and Metalloids
One major characteristic they have in common is they are metals.
At what temperature is water a gas
Answer:
212 degrees Fahrenheit
Explanation:
When liquid water reaches a low enough temperature, it freezes and becomes a solid—ice. When solid water is exposed to enough heat, it will melt and return to a liquid. As that liquid water is further heated, it evaporates and becomes a gas—water vapor.
What's the electron configuration of an N-3 ion?
Question 17 options:
A)
[Ne]
B)
[Ar]
C)
[H]
D)
[He]
Answer:
A. since Nitrogen has 7 electrons and when it gains 3 electrons it will have 10 electrons. using short hand rule it is [Ne]
Electron transfer between redox centers in proteins is controlled by quantum tunneling. We can model the region between two redox centers as an energy barrier which the electron must cross. If the distance between the redox centers is 0.681 nm and the energy of the electron is 0.5540.554eV lower than the height of the barrier, what is the probability that the electron will successfully cross to the next redox center
Answer:
5.61 e⁻³
Explanation:
Given that:
The barrier length = 0.681 nm = 6.81 × 10⁻¹⁰
The difference between the height of the barrier & the energy of the electron is;
[tex]V - E = 0.554 \ eV (1.6 \times 10^{-19} )[/tex]
= 8.864 × 10⁻²⁰ V
where;
m = 9.1 × 10⁻³¹ kg
The probability[tex]P = e^{-2 \ kd}[/tex]
[tex]k = 2 \pi \sqrt{\dfrac{2m (V-E)}{h^2} }[/tex]
[tex]k = 2 \pi \times \dfrac{\sqrt{2 \times 9.1 \times 10^{-31} \times 8.864 \times 10^{-20}}}{6.63 \times 10^{-34}}[/tex]
k = 3.806 × 10⁹
[tex]P = e^{-2 \ kd}[/tex]
[tex]P = e^{2 \times 3.806 \times 10^9 \times 6.81 \times 10^{-10}}[/tex]
P = 0.005606
P = 5.61 × 10⁻³
P = 5.61 e⁻³
Decide which element probably has a boiling point most and least similar to the boiling point of aluminum.
Comparing boiling point:
gallium rubidium magnesium oxygen
most similar to aluminum
least similar to aluminum
Answer:
The boiling point of gallium would be most similar to aluminum, and the boiling point of oxygen would be least similar to aluminum.
Explanation:
The atomic number of aluminum is 13, in the periodic table, magnesium lies in a similar period as Aluminum and Gallium is also present in a similar group. Thus, it can be expected that both magnesium and gallium exhibits similar boiling points with aluminum. However, gallium is a poor non-metal just like aluminum, while magnesium is a metal. Thus, it can be said that the boiling point of aluminum is more similar to gallium.
Now of the given elements, oxygen is a gas, thus, the boiling point of oxygen would be least similar to aluminum.
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Answer:
Yay
Explanation:
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Percent yield is very important in terms of money. The higher the percent yield, the more of a product you can make. If you are working for a drug company and your theoretical yield is 120 kg, but you actually made 105 kg, what is your percent yield?
A. 8.75%
B. 114%
C. 87.50%
D. 15.00%
Answer:
87.5 %
Explanation:
Step 1: Given data
Theoretical yield: 120 kgReal yield: 105 kgStep 2: Calculate the percent yield
When working with chemical reactions, we can determine the efficience in obtaining a product measuring the percent yield. The theoretical yield is the maximum amount of product that we could obtain according to the stoichiometry, whereas the real yield is the amount of product that we actually obtain when we carry out the process. We can calculate the percent yield usign the following expression.
%yield = real yield / theoretical yield × 100%
%yield = 105 kg / 120 kg × 100%
%yield = 87.5 %
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PLUS 30 PT
Why does DNA dissolve in water?
Why is salt added to solution of DNA and water?
How does ethanol help the precipitate form?
After a pellet is formed, is the DNA in the pellet or the supernate?
Explanation:
Because of this, DNA and RNA can easily dissolve in water. ... Adding ethanol helps the Na+ and PO3- ions come together, because ions travel easier in ethanol than water. The supernate is removed and new ethanol is added in the second washing. This removes any residual salt that remained on the pelleted DNA.
Answer:
DNA is polar due to its highly charged phosphate backbone. Its polarity makes it water-soluble (water is polar) according to the principle "like dissolves like". ... This fact makes water a very good solvent for charged compounds like salts.
Your DNA's sugar phosphate backbone is charged. By adding salt, we help neutralize the DNA charge and make the molecule less hydrophilic, meaning it becomes less soluble in water. The salt also helps to remove proteins that are bound to the DNA and to keep the proteins dissolved in the water.
It is well known that Ethanol has a lower dielectric constant than water, making it to promote ionic bond formations between the Na+ (from the salt) and the PO3- (from the DNA backbone), further, causing the DNA to precipitate.
Explanation:
Ideally DNA needs to be precipitated with pellet and should not remain in supernatant. DNA is acidic in nature and therefore, needs optimum salt concentration in the buffer to be pelleted from a solution. At very low salt concentration or without salt DNA would remain in supernatant.
Which set of terms best defines what affects kinetic energy and potential energy, respecrively
Which is the correctly balanced equation?
A) Cl2 + 2NaI = 2NaCl + I2
B) NaOH +HCl = NaCl + H2O2
C) 2HgO = Hg + O2
D) 2Li + H2O = 2LiOH + H2
PLS HURRY, TAKING TEST, NEED HELP NOW
Answer:
A) Cl2 + 2NaI = 2NaCl + I2
Help me please this is due today
What is a solute?
A material that is dissolved in another material.
O A material in which another material is dissolved.
An area of space surrounding the nucleus.
O Chemical formulas on the left side of an equation.