What % of original U238 remains after three half lives?
1-50
2-25
3-12.5
4-6.25

Answers

Answer 1

Answer:

12.5

Explanation:

After three half-lives, one eighth (1/2 x 1/2 x 1/2) of the uranium-238 will remain. One-eighth equals 12.5%


Related Questions

One component of smog is nitrogen
monoxide, NO. A car produces about 8 g of
this gas per day. What is the volume at STP?

Answers

Answer:

V = 5.97 L

Explanation:

Hello!

In this case, according to the ideal gas law:

[tex]PV=nRT[/tex]

We would need to solve for V as we know the temperature and pressure as the gas it at STP conditions (273 K and 1 atm respectively):

[tex]V=\frac{nRT}{P}[/tex]

Next, we compute the moles in 8 g of NO, given its molar mass of 30.01 g/mol:

[tex]n=\frac{8g}{30.01g/mol}=0.267mol[/tex]

Therefore, we obtain the following volume:

[tex]V=\frac{0.267mol*0.08206\frac{atm*L}{mol*K}*273K}{1atm}\\\\V=5.97 L[/tex]

Best regards!

help plz and will give brainly

Answers

I think D or C is my top answers

If you began a reaction with the following ions in solution, what would be the net ionic equation?
Na+, PO43–, Fe2+, and NO3–

Answers

Answer:

2 PO₄³⁻(aq) + 3 Fe²⁺(aq) ⇒ Fe₃(PO₄)₂

Explanation:

Let's consider the complete ionic equation between the ions present. It includes all the ions and the insoluble compounds (Fe₃(PO₄)₂ is insoluble).

Na⁺(aq) + 2 PO₄³⁻(aq) + 3 Fe²⁺(aq) + NO₃⁻(aq) ⇒ Fe₃(PO₄)₂ + Na⁺(aq) + NO₃⁻(aq)

The net ionic equation includes only the ions that participate in the reaction (not spectator ions) and the insoluble compounds.

2 PO₄³⁻(aq) + 3 Fe²⁺(aq) ⇒ Fe₃(PO₄)₂

Click to review the online content. Then answer the question(s) below, using complete sentences. Scroll down to view additional questions.

Online Content: Site 1


How did the gold rush transform Australia? (Site 1)






marking brainliest

Answers

Answer:

In 1851 gold-seekers from around the world began pouring into the colonies, changing the course of Australian history. The gold rushes greatly expanded Australia's population, boosted its economy, and led to the emergence of a new national identity.

Explanation:

Answer:

People from all over the world look for gold and in 1851 people started forming colonies to look for it which had a huge impact on the history of Australia.   The gold rushes increased Australia's population which improved its economy.

mathdrrggeszdrsz seer r-

Answers

Answer:

130!!

Explanation:

Which statement best describes the energy in the food web? A. The amount of energy available at level B depends on the amount of energy available at level C. B. The amount of energy available at level A depends on the energy provided from an abiotic source. C. The amount of energy available at level C is greater that the amount of energy available ate level A. D. The amount of energy available at level B is transferred to level A

Answers

Answer:

The amount of energy available at level A depend on energy provided from an a biotic source

5. Given the formula of a substance:
H Hн H
IT
C-C-C=C
1
H
H
What is the total number of shared electrons in a
molecule of this substance?
A) 22
B) 11
C) 9
D) 6

Answers

I think A and is the answer

A) 22

In a single bond one pair of electrons is shared, with one electron being contributed from each of the atoms. Double bonds share two pairs of electrons and triple bonds share three pairs of electrons. Bonds sharing more than one pair of electrons are called multiple covalent bonds.

In the given molecule:

There are total 7 single bonds and 2 double bonds.

As we know, In a single bond one pair of electrons is shared and double bonds share two pairs of electrons.

Thus,

Total number of shared electrons in a molecule= 7*2+2*4=14+8=22

So, total number of shared electrons in a molecule is 22.

Therefore, option A) is correct.

Learn more:

brainly.com/question/20602642

Whoever gets these 2 right gets brainliest! :)

Answers

the first one is A covalent bond.

the second one is Answer: B Decomposition

how many significant digits are in the number 1.0 × 10^3?​

Answers

121837481817381813727-
answer: 1000
1•10^3 add three 0’s

A molecule is the smallest part of a ?

Answers

Answer:

A molecule is the smallest particle in a chemical element or compound that has the chemical properties of that element or compound. Molecules are made up of atoms that are held together by chemical bonds. These bonds form as a result of the sharing or exchange of electrons among atoms.

Explanation:

Answer:

A molecule is the smallest part of an element, sorry if im incorrect

Help me with my homework plzy

Answers

Answer:

the second answer choice i think

Explanation:

If I’m correct, the answer is C) current electricity would become static electricity.

You have 0.531 L of gas in a container. What is the volume in mL?

Answers

Answer:

531 mL is the volume in mL

         

Answer:

Hi there!

I hope you are having an outstanding day.

I believe the answer to your question is 531!

Please adress me if I am incorrect. :)

Much love,

     Pandora

Explanation:

Can someone please help me!!

Answers

Answer:

Less in the top

your well wisher

A student plans a two-step synthesis of 1-ethyl-3-nitrobenzene from benzene. The first step is nitration of benzene to give nitrobenzene, and the second step is a Friedel-Crafts alkylation using CH3CH2Cl and AlCl3. The plan is flawed because: A : When the alkyl halide interacts with AlCl3, the resulting carbocation can rearrange before it has a chance to react with the aromatic ring. B : Nitrobenzene is too deactivated (by the nitro group) to undergo a Friedel-Crafts alkylation. C : The nitro group will direct the incoming alkyl group para position, rather than to the meta position. D : A blocking group is required to achieve this synthesis.

Answers

Answer:

Nitrobenzene is too deactivated (by the nitro group) to undergo a Friedel-Crafts alkylation.

Explanation:

The benzene ring in itself does not easily undergo electrophilic substitution reaction. Some groups activate or deactivate the benzene ring towards electrophilic substitution reactions.

-NO2 ia a highly deactivating substituent therefore, Friedel-Crafts alkylation of nitrobenzene does not take place under any conditions.

This reaction scheme is therefore flawed because Nitrobenzene is too deactivated (by the nitro group) to undergo a Friedel-Crafts alkylation.

State the coefficient required to correctly balance the following chemical equation:
_____ Ca3(PO4)2+ _____ NaCl ---------> _____ Na3PO4 + _____ CaCl2

Answers

Answer:

1 Ca3(PO4)2+ 6 NaCl ---------> 2 Na3PO4 + 3 CaCl2

Use the balanced equation in the image below. How many moles of
ammonia (NH3) will be produced if 2.22 moles of nitrogen (N2) are used?
(Assume there is excess hydrogen gas.) SHOW YOUR WORK TO RECEIVE
CREDIT. *
N2 + 3H2 → 2 NH3

Answers

Since there is excess hydrogen, that means that the concentration of hydrogen is not limiting.

According to the balanced chemical equation:

every mole of N2 and every 3 moles of H2 we obtain 2 moles of NH3. Since we have the amount of N2 and excess of hydrogen, we only need to work with the amount of N2.

1 mol of N2 will produce 2 moles of NH3

so now we can get a conversation tool :

moles of N2 * (2 moles of NH3/ 1 mole of N2) = moles of NH3

(2.22 mol of N2 x 2) ÷ 1 = 4.44 mol of NH3

pond water with microscopic organisms inside mixture or pure substance

Answers

Answer:

it's mixture

Explanation:

since pond is composed of not only microbes and also more aqatic animals so I think pond become mixture but not pure substance am I right or not...

How many grams equal 4.3 x 1024 atoms of oxygen (02)?

Answers

Answer: 248.66g

Explanation:

4.3e24 / 6.23e23 = 6.9 mols O2

6.9(18.02*2)=248.66

The equation below illustrates the process of
Pb2+ (aq) + 11- (aq) → Pblu (s)
a) dissolution
b) precipitation
c) decomposition

Answers

Answer:

The correct answer is - b) precipitation.

Explanation:

In the given question the lead ion in an aqueous solution is mixed with the Leutium ion in an aqueous solution and forms an insoluble or solid salt. This type of reaction is referred to as precipitation reactions in chemistry.

Such reactions are helpful in determining if a particular ion is present in the solution or not.

Pb2+ (aq) + lu- (aq) → Pblu (s)

A factory in your town uses cadmium as part of its manufacturing process. Due to recent economic conditions, cadmium is no longer available, and you must find a replacement. Suggest two elements that might be good replacements. Which of these would be your choice? Explain why.

Answers

Answer:

Zn

Explanation:

What is the atomic mass of element XX if 3.6 moles of the substance has a mass of 192 grams?

Answers

Answer:

53.3g/mol

Explanation

Moles=mass/molar mass

Molar mass= mass/moles

Molar mass= 192/3.6

= 53.3

how many moles of nitrogen gas are produced in the reaction if we started with 6 moles of ammonium nitrate

Answers

9moIN2 :
The molar ratio between Nitrogen and ammonia is
1
:
3
, therefore, to produce 18 moles of ammonia, we will need

thermal energy is what we call energy that come from ___ of matter

Answers

Temperature is your answer hopefully

Suppose an EPA chemist tests a 250.mL sample of groundwater known to be contaminated with nickel(II) chloride, which would react with silver nitrate solution like this: NiCl2(aq) + 2AgNO3(aq) → 2AgCl(s) + NiNO32(aq) The chemist adds 15.0mM silver nitrate solution to the sample until silver chloride stops forming. He then washes, dries, and weighs the precipitate. He finds he has collected 5.8mg of silver chloride. Calculate the concentration of nickel(II) chloride contaminant in the original groundwater sample. Round your answer to 2 significant digits.

Answers

Answer:

0.0010 w/v %

Explanation:

Based on the reaction:

NiCl₂(aq) + 2AgNO₃(aq) → 2AgCl(s) + Ni(NO₃)₂(aq)

Finding the moles of AgCl produced we can find the moles of NiCl in the reaction medium and its mass:

Moles AgCl -Molar mass: 143.32g/mol-:

5.8mg = 5.8x10⁻³g * (1mol / 143.32g) = 4.047x10⁻⁵ moles AgCl

Moles NiCl₂:

4.047x10⁻⁵ moles AgCl * (1mol NiCl₂ / 2mol AgCl) = 2.023x10⁻⁵ moles NiCl₂

Mass NiCl₂ -Molar mass: 129.60g/mol-:

2.023x10⁻⁵ moles NiCl₂ * (129.60g / mol) = 2.62x10⁻³g of NiCl₂ are produced.

And the concentration in w/v% is:

2.62x10⁻³g NiCl₂ / 250mL * 100 =

0.0010 w/v %

Which of these statements best supports the idea that a cell is the basic unit of a living organism?

A.
The number of cells in an organism affects the size of that organism.
B.
A tissue is composed of cells with similar structure and function.
C.
Some organisms have only one cell.
D.
All organisms are made up of one or more cells.

Answers

Answer:

The answer is D.

Explanation:

I searched it up :)

Guys please help me i will mark brainly!

Answers

Answer:

D

Explanation:

hi, if your looking for extra points (50+) and br ainiest here is ur chance, answer this question correctly plz

Answers

C! the others don’t make sense

Hydrogen has an oxidation number of +1 in all compounds excepts when it binds with metals and has an oxidation state of -1.​

Answers

Answer:

See explanation

Explanation:

In the periodic table, hydrogen is placed in group 1 for convenience. Hydrogen is not a metal, however, its common oxidation state is +1. It easily forms a univalent positive ion just like group 1 elements.

So, when hydrogen is combined with strongly electropositive metals such as sodium, lithium, etc, hydrogen accepts one electron and exhibits an oxidation state of -1 in those compounds.

Such compounds in which hydrogen is combined with strongly electropositive metals to give a binary compound is called a hydride.

I need help ASAP plz :)

Answers

can you reupload a clearer picture? i can help then

The percent by mass of iron(III) 1 Fe2S3
is _____%

Answers

Answer:

percent=69.94%

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