1. What fraction of a sample of N-16 remains undecayed after 42.78 seconds?

Answers

Answer 1

Answer:

1/64

Explanation:

From the question given above, the following data were obtained:

Time (t) = 42.78 s

Fraction of N–16 remaining (N/N₀) =?

NOTE:

N₀ => is the original amount.

N => is the amount remaining.

Next, we shall determine the number of half-lives that has elapsed. This can be obtained as follow:

Time (t) = 42.78 s

Half-life (t½) of N–16 = 7.1 s

Number of half-lives (n) =?

n = t / t½

n = 42.78 / 7.1

n = 6

Thus, 6 half-lives has elapsed.

Finally, we shall determine the fraction of N–16 that remains undecayed. This can be obtained as follow:

Number of half-lives (n) = 6

Fraction of N–16 remaining (N/N₀) =?

N = 1/2ⁿ × N₀

N = 1/2⁶ × N₀

N = 1/64 × N₀

Divide both side by N₀

N/N₀ = 1/64

Therefore, 1/64 of the sample remains undecayed.


Related Questions

PLEASE HELP ME ASAP!!! 10 POINTS!!

The three equations below represent nuclear fission and nuclear fusion reactions. For each equation, tell whether fission or fusion has occurred and write the missing term in the equation.

A) ²³⁵₉₂ U+n→⁹⁵₃₈Sr+____+2n

B) ³₁H+²₁H→⁴₂H+____

C) ____+n→⁹²₃₉Y+¹⁴⁰₅₃I+2n

Answers

Explanation:

A) fission: Iodine-140 (atomic number = 53)

B) fusion: 1 neutron

C) fission: Uranium-233 (atomic number = 92)

Si tuvieras que definir los atomos segun los postulados de Dalton, dirias que los atomos son particulas:

Answers

Answer:

Según el científico inglés John Dalton, los átomos son esferas elásticas e indivisibles. Así, según él, el átomo es el bloque de construcción más pequeño de la materia. Es homogéneo e indivisible, y todos los átomos de un elemento químico dado son idénticos (es decir, tienen el mismo conjunto de propiedades).

Aunque se descubrió a finales del siglo XIX que los átomos están hechos de partículas aún más pequeñas y pueden sufrir transformaciones, y que los átomos de un elemento dado pueden diferir ligeramente entre sí (isótopos), la teoría de Dalton fue la base para el desarrollo de la tecnología química moderna.

can someone help me sort this :(

Answers

Answer: A. is prey B. is predator C. is habitat D. is comunity E. is plants are producers and plant eating animals  consumors  F. is food chain G. is food web H. parasite I decomposers and scavengers J. is compete K an adsption

Explanation:


Mg + 2HCl → MgCl2 + H2
How many grams of Mg is needed to produce 100 g of H2?

Answers

H2

n=m÷Mr

n=100×2

n=200 moles

Mole ratio

Mg : H2

1 : 1

x : 200

cross multiply= x=200

Mg

make m the subject

m=n×Mr

m=200×24.305

m=4861 g

solute separates as a solid when a saturated solution is cooled why​

Answers

Answer:

When a saturated solution at a high temperature is cooled, why is the solution separated as a solid? When a saturated solution at a high temperature is cooled, inter molecular space between the molecules of the solution decreases. As a result, no more solute can remain in a solution separating out as a solid crystal.

A neutral atom has a ground state electron configuration of 1s22s22p63s2.The neutral atom becomes an ion during a chemical reaction.Which is the most likely charge of the ion

Answers

Answer:

+2

Explanation:

the atom will acquire the noble gas configuration if it loses 2 electrons, becoming a divalent cation

is NaHCO3 a binary compound​

Answers

Answer:

No

Explanation:

Binary compounds contain only 2 distinct elements.

For example magnesium oxide MgO is a binary compound.

NaHCO3 contains 4 distinct elements.

Riley let his friend borrow $12,750. He wants to be paid back in 57 months and is going to charge his friend a 5.5% interest rate. How much interest will his friend have to pay?

Answers

701.25 is how much his friend will have to pay back in interest

two ways the rate of a reaction be monitored

Answers

Answer:  If a reaction produces a gas such as oxygen or carbon dioxide, there are two ways to measure the reaction rate: using a gas syringe to measure the gas produced, or calculating the reduction in the mass of the reaction solution.

Explanation:

https://courses.lumenlearning.com/introchem/chapter/measuring-reaction-rates/#:~:text=If%20a%20reaction%20produces%20a,mass%20of%20the%20reaction%20solution.

This is the site I got it from.  I hope this helps.

How many molecules of fructose would you have if you have 0.7 moles of
fructose?
*

Answers

Answer:

4.214 × 10^23 molecules.

Explanation:

Number of molecules in a substance can be calculated by multiplying the number of moles in that substance by Avagadro's number, which is 6.02 × 10^23.

That is, no. of molecule = n × Avagadro constant

In this case, there are 0.7 moles of fructose. Hence;

number of molecules = 0.7 × 6.02 × 10^23

no. of molecule = 4.214 × 10^23 molecules.

The earth’s _____ creates a cross-current motion that captures the north and south moving air creating a ___ _____?

ANSWER AND YOU WILL BE MARKED BRAINLIEST (NO FILES) :))

Answers

Answer:

deflection,Coriolis effect

hope this helps

What color does blue brown and red make

Answers

Answer:

dark brown with a hint of purple

have a good day :)

Explanation:

If 3.4 mole of aluminum carbonate is exposed, how many moles of aluminum oxide will form?

Answers

0.0666
I got right
100%

which kind of climate do the most stable ecosystems tend to have?

A. Wet winters, dry summers

B. Cold winters, warm summers

C. cold and dry year-round

D. Warm and moist year round

Answers

B because the climate has to be pretty balanced and if it’s too cold it won’t be habitable and if the climate is too hot it won’t be habitable aswell

pls help me with this one (ignore what i pick)

Answers

Answer:

Its the second one i think

Explanation:

Coz liquid can move faster then a solid obviously :)

2Al + 3CuSO4–>3Cu+ Al2(SO4)3

If 2.75 g Al reacted completely with excess CuSO4 and the percent yield of Cu is 80.5%, what mass of Cu was produced?

Answers

Answer:

7.82 g of Cu

Explanation:

2 moles of Al react to 3 moles of copper sulfate in order to produce 3 moles of copper and 1 mol of aluminum sulfate.

Firstly we determine the moles of reactant.

As copper sulfate is in excess, Al is the limiting.

2.75 g . 1mol /26.98g = 0.102 moles

Ratio is 2:3. 2 moles of Al, can produce 3 moles of Cu

So the 0.102 moles of Al will produce(0.102 . 3) /2 = 0.153 moles.

We convert moles to mass: 0.153 mol . 63.5g /mol = 9.71 g

That's the theoretical yield (100 % yield reaction)

We know that: (yield produced / theoretical yield) . 100 = percent yield

We replace:

(Yield produced / 9.71g) . 100 = 80.5  %

(Yield produced / 9.71g) = 0.805

Yield produced = 0.805 .  9.71g = 7.82 g

What is the electron configuration of the sodium atom after it loses an electron?

Multiple choice question.

A)
1s22s22p6


B)
[He]2s22p5


C)
1s22s22p63s1


D)
1s22s22p63s1

Answers

Answer:

the answer is A 1s22s22p6

Helpp!! Please it’s balancing equations and I really need help in it it’s so hard theirs two other parts if you can help with those too:))

Answers

1.) 2=H2 1=O2 2=H2O
2.)
1st one - 2,6,2,3
2nd one - 2,2,1
3rd one - 1,2,2,1
4th one - 1,2,1,2

how many moles are 2.54 x 10^29 molecues of H2O

Answers

Answer:

[tex]\boxed {\boxed {\sf 421,786.7818 \ mol \ H_2O}}[/tex]

Explanation:

We are asked to convert from molecules of water to moles.

1. Avogadro's Number

1 mole of any substance contains the same number of particles (atoms, molecules, formula units, etc). This is Avogadro's Number: 6.022*10²³. In this problem, the particles are molecules of water.

2. Convert Molecules to Moles

Use Avogadro's Number to make a ratio.

[tex]\frac {6.022 *10^{23} \ molecules \ H_2O}{1 \ mol \ H_2O}[/tex]

Multiply by the number of molecules given: 2.54 *10²⁹

[tex]2.54 *10^{29} \ molecules \ H_2O \times \frac {6.022 *10^{23} \ molecules \ H_2O}{1 \ mol \ H_2O}[/tex]

Flip the ratio so the units of molecules of water cancel.

[tex]2.54 *10^{29} \ molecules \ H_2O \times \frac {1 \ mol \ H_2O}{6.022 *10^{23} \ molecules \ H_2O}[/tex]

[tex]2.54 *10^{29} \times \frac {1 \ mol \ H_2O}{6.022 *10^{23} }[/tex]

Condense the problem into 1 fraction.

[tex]\frac {2.54 *10^{29} }{6.022 *10^{23} }\ mol \ H_2O[/tex]

[tex]421786.7818 \ mol \ H_2O[/tex]

2.54 *10²⁹ molecules of water are 421, 786.7818 moles of water.

Calculate the moles of of Fe that would be needed to form 336 grams of Cl2 (round your answer to 2 decimals)

2Fe + 3Cl2 → 2FeCl3

Answers

Answer:

6.32 moles of Fe

Explanation:

The given chemical equation is presented as follows;

2Fe + 3Cl₂ → 2FeCl₃

The mass of Cl₂ in the reaction = 336 grams

The molar mass of chlorine gas Cl₂ = 35.435 g/mol

The number of moles, n = Mass/(Molar mass)

The number of moles of Cl₂ in the reaction, n = 336 g/(35.435 g/mol) ≈ 9.842 moles

From the given reaction, 3 moles of Cl₂ react with 2 moles of Fe to produce 2 moles of FeCl₃

By the law of definite proportions, we have that 9.482 moles of Cl₂ will react with approximately 9.482 × 2/3 = 6.32 moles of Fe to produce approximately 6.32 moles of FeCl₃

Therefore, approximately 6.32 moles of Fe will be required to react with 336 grams of Cl₂.

What is the molality of an acetic acid solution that contains 0.500 mol of HC2H3O2 (molar mass: 60g/mol) in 0.800 kg of water?

Answers

Answer: The molality of given acetic acid solution is 0.625 m.

Explanation:

Given: Moles of solute = 0.5 mol

Mass of solvent = 0.8 kg

Molality is the number of moles of solute present in a kg of solvent.

Therefore, molality of the given solution is calculated as follows.

[tex]Molality = \frac{moles}{mass of solvent}[/tex]

Substitute the values into above formula as follows.

[tex]Molality = \frac{moles}{mass of solvent}\\= \frac{0.5 mol}{0.8 kg}\\= 0.625 m[/tex]

Thus, we can conclude that the molality of given acetic acid solution is 0.625 m.

which statement best describes the difference between weather and climate
a) climate is about the hydrospace, weather is about autosphere
b) climate describes average temperature, weather describes many more factores
c) Climate is long periods of time, weather is short periods of time ( present day)
d) Climate describes conditions at sea level, weather describes conditions at different elevations

WILL MARK BRIANLIEST

Answers

Answer:

C

Explanation:

Brainliest

I tried my best

what are 2 factors that impact the flow of energy into and out of earths systems

Answers

Answer:

Solar energy causes evaporation; uneven heating of the Earth causes air masses to move; Coriolis forces help storms to take shape; and gravity makes rivers flow downhill. Another relevant factor is the high heat capacity (or specific heat) of water.

Explanation:

hoped this helped;)

how does Arizona's climate relate to the air and ocean currents?

Answers

Answer: In Arizona, climate change is already making deadly heat waves, droughts and wildfires across the state worse. These impacts have real costs on Arizonans' health and economy, including heat-related deaths, higher electricity bills, crop losses and more.

Explanation:

https://www.edf.org/climate/costofinaction- this is where I gathered this info.  Not mine.  But I hope it helps!

Oxygen (2) element name

Answers

Answer:

Oxygen has two allotropic forms, diatomic (O₂) and triatomic (O₃, Ozone).

-TheUnknownScientist

PLEASE HELP ME (JOULES)

Type the correct answer in the box. Round your answer to the nearest whole number.
Dina has a mass of 50 kilograms and is waiting at the top of a ski slope that’s 5 meters high.
The maximum kinetic energy she can reach when she skis to the bottom of the slope is
joules.
Use PE = m × g × h and g = 9.8 m/s2. Ignore air resistance and friction.

Answers

Answer:

2450 joules

Explanation:

The formula for potential energy is PE = m x g x h

m is the mass, in kg (50)

g is the acceleration due to gravity, in meters per second squared (9.8)

h is the height, in meters (5)

The problem gives m = 50, g = 9.8, and h = 5. Plug that into the formula and get the answer.

[tex]PE = mgh\\PE = (50) (9.8) (5)\\PE = 2450[/tex]

According to law of conservation of energy and substitution of values in formula gives,2540 joules as maximum kinetic energy.

What is law of conservation of energy?

According to law of conservation of energy, it is evident that energy  is neither created nor destroyed rather it is restored at the end of a chemical reaction .

Law of conservation of mass and energy are related as mass and energy are directly proportional which is indicated by the equation E=mc².Concept of conservation of mass is widely used in field of chemistry, fluid dynamics.

Law needs to be modified in accordance with laws of quantum mechanics under the principle of mass and energy equivalence.Substitution in formula gives , PE=50×9.8×5=2540 J.

Thus, the maximum kinetic energy she can reach when she skis to the bottom of the slope is 2540 J.

Learn more about law of conservation of energy,here:

https://brainly.com/question/29775341

#SPJ7

What type of chemical reaction does this equation represent?

Ag2S + KCN --> AgCN + K2S

Answers

The type of chemical reaction is "Double displacement"

hurricanes typically form over A: Warm ocean water B: Tropical rainforest C: Very dry land masses D: COLD ocean water​

Answers

Answer:

A.) Warm Ocean Waters

Explanation:

Hurricanes usually originate within hotter climates but must have a direct or large body of water to form over. In this case, majority of the hurricanes reported originated over large bodies of water such as Oceans near the equator. This is so because with intense humidity and high pressured areas hurricanes began to collect vapor which begins to swirl in a spiral format. Many hurricanes in fact occur rather near the equator.

Fun Fact: Hurricanes usually occur among coastal lines located closer to the equator. Such as, within the US, hurricanes up north are considered to be quite rare given the usual cold environment in comparison to the southern states.

What is anything has mass and volume called?

Answers

Answer:

Matter

Explanation:

It has mass and it takes up space

Which of the following relationships is true?
A. pH − pOH = 14
B. Ka × Kb = 1 × 10-14
C. pKa × pKb = 14
D. pKa × pKb = 1 × 10-14

Answers

Answer:

D. pKa × pKb = 1 × 10-14

Explanation:

hope this helps, if not, give me time to edit

Answer:

B. Ka × Kb = 1 × 10-14

Explanation:

yw

Other Questions
Which of the following choices is the best antonym forthe underlined word in this sentence?A freckle that is more than 1" across, has irregularsides, or is green may be a sign of an abnormal growth.Select one:A: weirdB: unhealthyC:strangeD:typicalAbnormal is the underlined word. this is only for (the brain)!!!!!!!! i will give you something that can help you reach the level you need to be on. A cable that is 45 feet long is attached to the top of a vertical pole. The cable is anchored to the ground 36 feet from the base of the pole . How tall is the pole? Round your answer to the nearest hundredth . Please help me !!!!! HELP HELP PLEASE PLEASE HELP!! GIVING BRAINIEST IF CORRECT!!!!!Out of 300 diners, 60 ordered salads. What percent of diners ordered a salad?A. 2%B. 20%C. 5%D. 15% What is the median number of TVs in Mrs. Jamison's Class? The following question has two parts. Answer Part A first, and then Part B.Part A What type of figurative language is used in the following sentence from the story?It was stuck to Jess's knee like gum to the bottom of a shoe.O idiomO simile cheO metaphorO personification Identify and explain three different ways Lieutenant Dan and Bubba related differently to the war in Vietnam. Question 12SolveThe distance, s(t), in feet traveled by a freely falling object is given by the function s(t) = 162, wheret is time in seconds. Use this formula to find the time it would take for an object to fall to theground from a cliff that is 1024 feet high.7 sec64 sec8 sec9 sec What is the y-intercept 54 is 32% of what number? Round to the nearest hundredth if necessary. 25 POINTS AND BRAINLIEST WHOEVER ANSWERS At a glass vase store, 88 out of the last 20 vases shipped were chipped. What is the experimental probability that the next vase shipped will be chipped? ANSWER AS PERCENTAGE Select the correct answer.Which section of a research paper contains all the sources that are cited in the paper?.abstractOB.bibliographyOC.review of literatureODanalysisthingResetNext how does the title related to the book of dead stars? I NEED HELP FAST PLEASEEEEEEE Groups of locally trained soldiers in the American colonies were called _____.A. RedcoatsB. sons of libertyC. militias Finding ways to reach agreement with the Soviet Union on critical issues due to relaxing tensions is referred to as:A. Nixon DoctrineB. RapprochementC. DtenteD. Glasnost Some pre algebra question idrk Graph points (-4,-1) (4, 3). Write the equation of the line that passes through the points in slope-intercept form.Hurry please! I need it by the next 15 minutes . A nearsighted person has a far point of 25.525.5cm and is prescribed contact lenses to correct her vision. What lens strength (a.k.a., lens power), in Diopters, should be prescribed