An 80g sample of 3 1 H decays, leaving 2.5g of 3 1 H.
1. How long would this take?
2. What percentage of this sample would be left?
3. What fraction of this sample would be left?

3 1 H -> 3 2 He + 0 -1 /3 t1/2= 12.3 years

Answers

Answer 1
Here is the link to the answer:

Related Questions

A molten metal that catches fire in chlorine gas and gives off white fumes?​

Answers

Answer:

please give me brainlist and follow

Explanation:

sodium

The molten metal that catches fire in chlorine gas and gives off white fumes is sodium. The metal that forms two types of its oxide and rust in moisture is iron. The formulas of its oxides are : FeO;Fe2O3. The metal used in hot water systems is copper, because it is a good conductor of heat and electricity.

Answer:

I think it is Sodium not sure but try

Whose ideas were based on scientifically gathered evidence?
A. Aristotle and alchemists
B. Aristotle and John Dalton
C. John Dalton and Marie Curie
D. Marie Curie and alchemists

Answers

Answer:

Maybe c?

Explanation:

John Dalton was an English chemist, and Marie Curie was a physicist and chemist. The ideas of John Dalton and Marie Curie were based on scientifically gathered evidence. Thus, option C is correct.

Who are John Dalton and Marie Curie?

John Dalton and Marie Curie are famous physicists and chemists. John Dalton is most known for introducing the theory of the atom and color blindness. He gave the theory of atomism based on the experimental setup.

Marie curie hugely contributed to the discovery of radioactivity and cancer research. She and her husband experimented and searched for the radioactive material.

Aristotle was a philosopher and established the relation between the various fields of sciences. He originated the idea of Alchemy by combining the four elements.

Therefore, John Dalton and Marie Curie proposed ideas based on research.

Learn more about Marie Curie here:

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#SPJ2

True or false: to get 8 valence electrons, oxygen can borrow or share some electrons

Answers

Answer:

True

Explanation:

In ionic compounds, oxygen borrows electrons. In covalent compounds, oxygen shares electrons.

i If a chemical system is at equilibrium, any change in the system will always result in an increase of which of the following?

1.The reaction that opposes the change

2. The concentration of the product

3. The concentration of the reactants

4. The temperature of the system​

Answers

Answer:

1.The reaction that opposes the change

Explanation:

Consider the reaction;

A + B ⇄ C + D

If a constraint such as a change in temperature, pressure or volume is imposed on this chemical system in dynamic equilibrium, the equilibrium position will shift so as to annul the constraint.

This shift in the equilibrium position will favour either the forward or reverse reaction depending on the type of constraint imposed on the system.

Hence, If a chemical system is at equilibrium, any change in the system will always result in an increase of the reaction that opposes the change.

How many molecules are in 0.500 mol of AlBr3

Answers

.500 mol ( 6.02x10^23 molecules/1 mol) = 3.01x10^23        

What is the molarity of a Sodium Chloride solution if 86.00g of NaCl was dissolved in enough water to form 1000.mL of solution?

Answers

Answer:

1.47 M

Explanation:

First we convert 86.00 g of NaCl into moles of NaCl, using the molar mass of NaCl:

86.00 g ÷ 58.44 g/mol = 1.472 mol NaCl

Then we convert 1000 mL into liters:

1000 mL / 1000 = 1.0 L

Finally we can calculate the molarity of the solution:

Molarity = moles / liters1.472 mol / 1.0 L = 1.472 M

3. What is the current in a wire
that has a resistance of 2.5 Q
and is connected to a 12 V
battery?

Answers

4.8A
12/2.5=4.8, the current in this wire should be 4.8A

What combinations of up and down did quarks combine to make the proton?

A. Down + down + down
B. Up+Up+ down
C. Up+Up+Up
D. Up+down+down
E. Up+down

Answers

Answer:

it is b

Explanation:

b is the quarks for a proton

Answer:

B

Explanation:

HELP HELP HELP HELP!!!!!!!

Answers

Answer:

About 200 moles water

Explanation:

O2 is the limiting reactant, and it allows for 193.75 moles of water to be produced. Good luck on your assignment!

What is the mass of a 0.5 mol sample of C2H6?

Answers

Answer: 30.08 g/mol

Explanation:

C2= 12.01 H6=1.01

12.01(2) + 1.01(6) =

24.02 + 6.06 =

30.08 g/mol

what blood vessels and chambers of the heart does a red blood cell pass as it delivers oxygen from the lungs to the brain and return to be oxygenated again.

Answers

Answer:

capillaries

Explanation:

hope it helps if I'm not tell me right away.

Answer:

Carotid artery, Jugular veins

The chambers are explained below.

Explanation:

THE BLOOD VESSELS

The carotid artery carries red blood (oxygenated) to the head and the neck region and that obviously include the brain via the aorta. To be precise the internal carotid artery supplies oxygenated red blood cells to brain. The jugular veins carry deoxygenated red blood cells from the head back to the heart via the superior vena cava. The most important function of the jugular vein is to drain deoxygenated blood from brain.

THE CHAMBERS

The left atrium receives oxygenated blood from the lungs and pumps it to the left ventricle which also pumps the same oxygenated blood to the rest of the body through the aortic valve (aorta).

The right atrium receives deoxygenated blood from the body via the vena cava  and pumps the deoxygenated blood to the right ventricle which pumps the deoxygenated blood to be oxygenated by the lungs via the pulmonary valve (pulmonary artery).

CONCLUSION

The oxygenated red blood cells from the lung pass through the pulmonary vein through the left atrium to the left ventricle through the carotid artery (internal carotid artery) via the aorta to the brain and

The deoxygenated red blood cells in the brain are drained through the jugular vein via the superior vena cava to the right atrium, which pumps the deoxygenated blood to the right ventricle. From here the deoxygenated blood is pumped to the lungs via the pulmonary artery for oxygenation.

This is my answer, thus if I got your question right.

When you draw a bow'across a violin string, which kind of wave is created in
the air surrounding the string?
A. surface
B. electromagnetic
C. longitudinal
D. Transverse

Answers

Answer:

C

Explanation:

Answer: C. Longitudinal

Explanation: A P 3 X

Pls help :( <3333333

Answers

Answer:

Option C

Explanation:

Look here,

3CuCl2 + 2Al --> 2AlCl3 + 3Cu

On

LHS = 3Cu , 3 × Cl2 = 6Cl and 2Al

RHS = 2Al , 2 × Cl3 = 6Cl and 3Cu

Hence,

LHS = RHS and the above equation is balanced

The petrol additive tetraethyl-lead (IV), Pb(C2H3)4, is now
banned in many countries. When it is completely burned in air,
lead (II) oxide, CO, and H2O are formed. How many moles of
oxygen are required to burn one mole of Pb(C2H5)?

Answers

Answer:

9.5 mol

Explanation:

Let's consider the unbalanced equation for the combustion of tetraethyl-lead (IV).

Pb(C₂H₅)₄ + O₂ ⇒ PbO + CO + H₂O

Pb atoms are balanced. We will balance C atoms by multiplying CO by 8.

Pb(C₂H₅)₄ + O₂ ⇒ PbO + 8 CO + H₂O

Then, we will balance H atoms by multiplying H₂O by 10.

Pb(C₂H₅)₄ + O₂ ⇒ PbO + 8 CO + 10 H₂O

Finally, we get the balanced equation by multiplying O₂ by 9.5.

Pb(C₂H₅)₄ + 9.5 O₂ ⇒ PbO + 8 CO + 10 H₂O

All in all, we need 9.5 moles of O₂ to burn 1 mole of Pb(C₂H₅)₄.

1.35 m solution NaOCl in water is prepared. What is the mole fraction of the NaOCl?

Answers

Answer:

NaOCl + H2O → HOCl + NaOH

so the mole fraction is = moles of NaOCl/(moles of NaOCl+moles of H2O)

so for 1.35 NaOCl it will require 1.35 moleof H2O

mole fraction = 1.35/(1.35+1.35)

mole fraction = 1/2 =0.5

is it correct i d ek but i tried :)

The mole fraction of the NaOCl is 0.0237

We'll begin by calculating the mole of solute (NaOCl) in the solution.

Molality = 1.35 mMass of water = 1 KgMole of NaOCl =?

Mole = Molality x mass (Kg) of water

Mole of NaOCl = 1.35 × 1

Mole of NaOCl = 1.35 mole

Next, we shall determine the mole of water.

Mass of water = 1 Kg = 1000 gMolar mass of water = 18.01 g/mol Mole of water =?

Mole = mass / molar mass

Mole of water = 1000 / 18.01

Mole of water = 55.52 moles

Finally, we shall determine the mole fraction of NaOCl.

Mole of NaOCl = 1.35 moleMole of water = 55.52 moles Total mole = 1.35 + 55.52 = 56.87 moles Mole fraction of NaOCl =?

Mole fraction = mole / total mole

Mole fraction of NaOCl = 1.35 / 56.87

Mole fraction of NaOCl = 0.0237

Learn more about mole fraction:

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1)
Steel Wool Experiment
Before
Observations
After
Observations
Appearance
Steel wool dark gray,
Balloon deflated
Appearance
Steel wool dark
brown; Balloon
inflated
Mass (9)
485.68
Mass (9)
The students data can be seen here. A chemical reaction clearly took
place in the flask. One entry is missing: the mass of the system at the
end of the experiment. What amount should be added to the data
table?

Answers

Answer:

Chemical reactions, chemistry, science as inquiry and data analysis. ... Students burn steel wool in both an open and closed environment to understand ... The difference in mass for this small sample of steel wool will be very small. ... careful attention to the balloon! 9. When rusting occurs the properties of the metal changes.

Explanation:

Is photosynthesis endothermic or exothermic, why?

A. Endothermoc, energy is needed to oxidize water so it can eventually be stored in sugars. Free energy is temperature dependent.
B. Exothermic, energy is needed to oxide water so it can eventually be stored in sugars. Free energy is not temperature dependent.
C. Endothermic, energy is needed to oxidize water so it can eventually be stored in sugars. Free energy is not temperature dependent.
D. Exothermic, energy is needed to reduce water so it can eventually be stored in sugars.
E. Exothermic, energy is needed to oxidize water so it can eventually be stored in sugars.
F. Exothermic, energy is needed to oxidize water so it can eventually be stored in sugars. Free energy is temperature dependent.
G. Endothermic, energy is needed to reduce water so it can eventually be stored in sugars.

Answers

Answer: I think A is right

Explanation: Photosynthesis needs light so it is endothermic,

Oxygen in water is oxidised and Oxygen is released in process.

Free energy is temperature dependent. But also Carbo dioxide

involves reaction. You needs to find out Calvin-Benson cycle

Indicate whether the following processes are spontaneous or nonspontaneous. (a) Liquid water freezing at a temperature below its freezing point (b) Liquid water freezing at a temperature above its freezing point (c) The combustion of gasoline (d) A ball thrown into the air (e) A raindrop falling to the ground (f) Iron rusting in a moist atmosphere

Answers

Answer:

The correct answer is -

(a) spontaneous;

(b) nonspontaneous;

(c) spontaneous;

(d) nonspontaneous;

(e) spontaneous;

(f) spontaneous

Explanation:

(a) Liquid water freezing at a temperature below its freezing point.

in this reaction, there is no requirement of external energy or force to make it possible due to the fact that the temperature of the environment is less than the freezing point of water. So, the water will spontaneously freeze.

(b) Liquid water freezing at a temperature above its freezing point. the melting of ice takes place with the increase or absorbing the heat which is a nonspontaneous,

(c) The combustion of gasoline produces gas molecules, and release energy which means it is an exothermic reaction, the combustion of gasoline is a spontaneous reaction.

(d) A ball is thrown into the air is not a natural process and it requires force or energy to be complete and works against gravity, Therefore, it is a nonspontaneous reaction.

(e) A raindrop falling to the ground is a naturally occurring reaction without any external force and in the direction of gravity, thus it is a spontaneous reaction.

(f) Iron rusting in a moist atmosphere is a spontaneous reaction as it does not require energy to occur and it naturally takes place. It is a redox reaction.

Which of the following has to remain constant to allow you to use the combined gas law for calculations?
O A pressure
ОВ.
volume
Oc.
temperature
OD.
amount of gas

Answers

Answer:

Amount of gas

Explanation:

The combined gas law has to do with pressure, volume, and temperature. All of them can be a variable that you have to solve for. However, amount of gas is not a variable you can solve for, which means it must remain constant.

What is 1 x 102 divided by 1 x 10-3?
O 1x 10-6
O 1x 10-1
0 1x 103
O 1 x 105

Answers

Answer:

Option (d) is correct.

Explanation:

Let [tex]x=10^2[/tex] and [tex]y=10^{-3}[/tex].

We need to find the value of [tex]\dfrac{x}{y}[/tex].

Put the values of x and y such that,

[tex]\dfrac{x}{y}=\dfrac{10^2}{10^{-3}}\\\\=10^2\times 10^3\ (As\ \dfrac{1}{x^{-a}}=x^a)\\\\=10^5\ (As\ x^a\times x^b=x^{ab})\\\\=1\times 10^5[/tex]

So, the required answer is equal to [tex]1\times 10^5[/tex]. Hence, the correct option is (d).

Convert 550 torr into SI units.

Question 10 options:



1 atm




73,326 Pa




101,325 Pa




700 mm Hg

Answers

Answer:

73,326 Pa

Explanation:

73,326 Pa

What is the meaning of a null hypothesis being rejected?
The hypothesis is definitely correct.
The hypothesis might be correct.
The hypothesis is false.
The null hypothesis is correct.

Answers

Answer:

the hypothesis is false

Explanation:

it I rejected because the hypothesis has been tested severally and the answer still proves to be wrong

Answer:

probably the third option: The hypothesis is false

Explanation:

Please help me! It’s past due but he giving me 15 mins!

Answers

1. C3H8 + 5O2 —> 3CO2 + 4H2O
2. 2Al + Fe3N2 —> 2AlN + 3Fe
3. 2Na + Cl2 —> 2NaCl
4. 2H2O2 —> 2H2O + O2
5. C6H12O6 + 6O2 —> 6H2O + 6CO2
6. 4H2O + 7CO2 —> C7H8 + 9O2
7. 2NaClO3 —> 2NaCl + 3O2
8. 4(NH4)3PO4 + 3Pb(NO3)4 —> Pb3(PO4)4 + 12NH4NO3
9. 2BF3 + 3Li2SO3 —> B2(SO3)3 + 6LiF
10. 4C7H17 + 45O2 —> 28CO2 + 34H2O
11. 3CaCO3 + 2H3PO4 —> Ca3(PO4)2 + 3H2CO3
12. 8Ag2S —> 16Ag + S8
13. 3KBr + Fe(OH)3 —> 3KOH + FeBr3
14. 2KNO3 + H2CO3 —> K2CO3 + 2HNO3
15. Pb(OH)4 + 2Cu2O —> PbO2 + 4CuOH
16. Cr(NO2)2 + (NH4)2SO4 —> CrSO4 + 2NH4NO2
17. 6KOH + Co3(PO4)2 —> 2K3PO4 + 3Co(OH)2
18. 3Sn(NO2)4 + Pt3N4 —> Sn3N4 + 3Pt(NO2)4
19. B2Br6 + 6HNO3 —> 2B(NO3)3 + 6HBr
20. 3ZnS + 2AlP —> Zn3P2 + Al2S3

How much heat will be absorbed when 38.2 g of bromine reacts with 12.4g of hydrogen according to the following equation?
H2 + Br2 + 72.80 = 2HBr

Answers

Answer:

17.4 kJ

Explanation:

If have a volume of 18 L of a gas at a temperature of 272 K and a pressure of 90 atm, what will be the pressure of the gas if raise the temperature to 274 Kand decrease the volume to 12 L?

Answers

Answer:

P₂ ≅ 100 atm (1 sig. fig. based on the given value of P₁ = 90 atm)

Explanation:

Given:

P₁ = 90 atm                    P₂ = ?

V₁ = 18 Liters(L)              L₂ = 12 Liters(L)      

=> decrease volume => increase pressure

=> volume ratio that will increase 90 atm is (18L/12L)                                                                  

T₁ = 272 Kelvin(K)          T₂ = 274 Kelvin(K)

=>  increase temperature => increase pressure

=> temperature ratio that will increase 90 atm is (274K/272K)

n₁ = moles = constant    n₂ = n₁ = constant

P₂ = 90 atm x (18L/12L) x (274K/272K) = 135.9926471 atm (calculator)

By rule of sig. figs., the final answer should be rounded to an accuracy equal to the 'measured' data value having the least number of sig. figs. This means P₂ ≅ 100 atm based on the given value of P₁ = 90 atm.

PLZ HELP I WILL GIVE BRAINLIEST!!!
The light is most intense where it strikes Earth ___________ to its surface.

Answers

Answer:

the sun's Rays strike Earth surface most directly at the Equator this focuses the race on a small area because be raised hit more directly the area is heated more

Explanation:

yw

Ametal added to gold to harden it ?​

Answers

Answer:

copper

Explanation:

Copper is used as a base metal to mix with gold and to make it stronger, harder and less brittle in nature. It acts as the best alloy to make ornaments. Since the Silver layer gets easily oxidized in nature and gets easily corroded, copper remains the best choice as a metal to mix with Gold.

Sruthi accidentally poured salt into the lemonade she was making instead of sugar. Can Sruthi remove all the salt by pouring it through a filter? Explain why or why not. 2 marks need answers ASAP, I'll mark brainliest if correct.

Answers

Answer:

Yes you can!

Explanation: Here is one method i did in school you can put a cup of the salted lemonade into a big container seal it off and put plastic inside heat it up and the water will evaporate and leak from the sides while the salt will stay in the cup. Pls give me brainliest

probably something to do with the acid in the lemonade. the acidic lemonade may dissolve salt better and faster than sugar.

What is the pH of a solution with a concentration of 0.000012 H+ ions?

Answers

Answer:

pH ≈ 4.92

Explanation:

pH = -log(0.000012)

pH ≈ 4.92

#1 pls help me complete

Answers

Answer:

n = 0.045 mol.

Explanation:

Hello there!

In this case, according to the given problem, we can firstly set up the ideal gas equation as shown below:

[tex]PV=nRT[/tex]

Thus, as we are asked to calculate the moles, we proceed as follows:

[tex]n=\frac{PV}{RT}[/tex]

Therefore, we plug in the given data to obtain:

[tex]n=\frac{760mmHg*\frac{1atm}{760mmHg}*1.0L}{0.08206\frac{atm*L}{mol*K}*273K} \\\\n=0.045mol[/tex]

Best regards!

Other Questions
Crystal Displays Inc. recently began production of a new product, flat panel displays, which required the investment of $1,500,000 in assets. The costs of producing and selling 5,000 units of flat panel displays are estimated as follows:Question not attempted.1 Variable costs per unit:2 Direct materials $120.003 Direct labor 30.004 Factory overhead 50.005 Selling and administrative expenses 35.006 Total $235.007 Fixed costs:8 Factory overhead $250,000.009 Selling and administrative expenses150,000.00Crystal Displays Inc. is currently considering establishing a selling price for flat panel displays. The president of Crystal Displays has decided to use the cost-plus approach to product pricing and has indicated that the displays must earn a 15% rate of return on invested assets.Required:1. Determine the amount of desired profit from the production and sale of flat panel displays.2. Assuming that the product cost conceptA concept used in applying the cost-plus approach to product pricing in which only the costs of manufacturing the product, termed the product cost, are included in the cost amount to which the markup is added.is used, determine (a) the cost amount per unit, (b) the markup percentage, and (c) the selling price of flat panel displays.3. (Appendix) Assuming that the total cost conceptA concept used in applying the cost-plus approach to product pricing in which all the costs of manufacturing the product plus the selling and administrative expenses are included in the cost amount to which the markup is added.is used, determine (a) the cost amount per unit, (b) the markup percentage (rounded to two decimal places), and (c) the selling price of flat panel displays (rounded to nearest whole dollar).4. (Appendix) Assuming that the variable cost conceptA concept used in applying the cost-plus approach to product pricing in which only the variable costs are included in the cost amount to which the markup is added.is used, determine (a) the cost amount per unit, (b) the markup percentage (rounded to two decimal places), and (c) the selling price of flat panel displays (rounded to nearest whole dollar).5. Comment on any additional considerations that could influence establishing the selling price for flat panel displays.6. Assume that as of August 1, 3,000 units of flat panel displays have been produced and sold during the current year. Analysis of the domestic market indicates that 2,000 additional units are expected to be sold during the remainder of the year at the normal product price determined under the product cost concept. On August 3, Crystal Displays Inc. received an offer from Maple Leaf Visual Inc. for 800 units of flat panel displays at $225 each. Maple Leaf Visual Inc. will market the units in Canada under its own brand name, and no variable selling and administrative expenses associated with the sale will be incurred by Crystal Displays Inc. The additional business is not expected to affect the domestic sales of flat panel displays, and the additional units could be produced using existing factory, selling, and administrative capacity.A. Prepare a differential analysis of the proposed sale to Maple Leaf Visual Inc. Refer to the lists of Labels and Amount Descriptions for the exact wording of the answer choices for text entries. For those boxes in which you must enter subtracted or negative numbers use a minus sign. If there is no amount or an amount is zero, enter "0". A colon (:) will automatically appear if required.B. Based on the differential analysis in part (A), should the proposal be accepted? The formula v= u + at can be used to calculateRearrange the formula to make u the subject. please solve this I will mark brainleistttttttttt hari frequently visits IIlam.(negative). A common misconception is that the muscular system only moves bones. Why is this statement incorrect? Explain the idea correctly. Why might some people have this misconception? Cite facts from the readings in your answer. Also cite what you may already know about the topic in your answer. What natural disaster led to famine for many African nations during the1980's? how doe your parasympathetic nervous system use feedback to keep you healthy?a. it triggers a fight-or-flight response when danger has passed.b. it dilates your pupils when you are in bright light.c. it lowers your heart rate after danger has passed d. it calms you down when you are in danger. explain how the Chinese writing system was similar to the Egyptian writing i need help with all of thies Problem 7-2A (Algo) Estimating and reporting bad debts LO P2, P3 Skip to question [The following information applies to the questions displayed below.] At December 31, Hawke Company reports the following results for its calendar year. Cash sales $ 1,392,180 Credit sales $ 3,376,000 In addition, its unadjusted trial balance includes the following items. Accounts receivable $ 1,022,928 debit Allowance for doubtful accounts $ 22,240 debit Problem 7-2A (Algo) Part 1 Required: 1. Prepare the adjusting entry to record bad debts under each separate assumption. Bad debts are estimated to be 2% of credit sales. Bad debts are estimated to be 1% of total sales. An aging analysis estimates that 5% of year-end accounts receivable are uncollectible. The rate law, rate constant, and reactant concentrations for the reaction of nitrogen dioxide with oxygen are given. What is the rate of the reaction under these conditions?R = k[NO]2[O2], k = 7,000 M-2 s-1 [NO] = 0.040 M, [O2] = 0.060 MA. R = 7,000 M-2 s-1B. R = 16.8 s-1C. R = 0.672 M s-1D. R = 0.040 M2 s-1 President Abraham Lincoln wanted the North to fight in the civil war in order tokeep the United States as one country.O split the United States into regions.help the farmers in the United States.O establish colonies in the United States. **NO LINKS and please no fake answers** If you've seen Darwin's Dangerous idea NOVA HD, could you give 20 facts from the video? (Less is fine too ofc, 20 is a lot)Will give brainliest :) If I roll a dice 120 times how many times I expect to get a 2 HELP ME PLEASE!!!this is due in 10 minutesThe lengths of the sides of a triangle are x,2x and 2x centimetres.If the perimeter is 20 centimeters,what is the value of x?a)4b)5c)8d)10 Select the correct text in the passage.Which part of this excerpt from Jhumpa Lahiri's "Once in a Lifetime" indicates Hema's mother's Bengali heritage?I asked how long you would be staying with usa week? Two? My mother couldn't say; it all depended on how long it took your family to get settled and find a place. The prospect of having to give up my room infuriated me. My feelings were complicated by the fact that, until rather recently, to my great shame, I'd regularly slept with my parents on the cot in their room, and not in the room where I kept my clothes and things. My mother considered the idea of a child sleeping alone a cruel American practice, and therefore did not encourage it, even when we had the space. Find the area of a trapezoid with a base of 21.6 m, a height of 4.5 m, and top of 11.9 m. Round your answer to the nearest hundredth. 11.9 m 14.5 m 21.6 m April Fool's is the first day of April. Fact or Inference? (Explain) PLEASE ACTUALLY HELP Why and how did the turn of the century become an era of reform? Which function is represented by this graph?