2.Uranium-235 has a half-life of about 700 million years. If 1 kg of U-235 is put on a shelf in
a laboratory, how much of it will be left after 700 million years? (5 points)

Answers

Answer 1

Answer:

.5 kg

Explanation:

At the start of Uranium-235 there is a total of 1 kg. Uranium-235 half life is 700 million years, take 1kg ÷2 = 0.5kg after 1 half life.

Let's say another 700 million years go by that means you take 0.5kg and divide that by 2.

0.5kg÷2= 0.25 kg is left after 2 half lives.

Hope this helps good luck!


Related Questions

Consider the following reaction where Kc = 55.6 at 698 K.

H2(g) + I2(g) 2HI(g)

A reaction mixture was found to contain 2.29×10-2 moles of H2(g), 3.80×10-2 moles of I2(g) and 0.254 moles of HI(g), in a 1.00 liter container.

Is the reaction at equilibrium?
If not, what direction must it run in order to reach equilibrium?

The reaction quotient, Qc, equals
.

The reactionfill in the blank 2

A. must run in the forward direction to reach equilibrium.
B. must run in the reverse direction to reach equilibrium.
C. is at equilibrium.

Answers

Answer:

B

No the reaction is not at equilibrium

The reaction must run to the left (reactants) to reach equilibrium

Qc = 74.14

Explanation:

Qc = (0.254)^2 / ((2.29 x 10-2)(3.8 x 10-2))

Qc = 74.14

74.14 > 55.6

Qc > Kc

Which substance will hold its shape?

plasma
liquid
gas
solid

Answers

Answer:

solid

Explanation:

plasma = no

liquid= shapes is container it is in

gas = shaped to container also


Reactivity Series
Iron, tin and zinc all react with dilute hydrochloric acid to produce hydrogen.
Plan an experiment to determine the order of reactivity of iron, tin and zinc.
You are provided with powdered samples of the metals and common laboratory apparatus.

Answers

Answer:

Measuring electode potential

Explanation:

Make an electrode of all of them and measure standard reductive potential metals with lower srp will be more reactive

The metals which are placed above the hydrogen in the reactivty series can produce hydrogen gas with HCl. The order of reactivity of given metals is as follows: Zinc > iron > tin.

What is reactivity series?

The reactivity series of elements or the activity series can be defined as the arrangement of metals in descending order according to their reactivities.

The metals placed at the top of the activity series are strong reducing agents and can be readily oxidized. These metals readily tarnish/corrode. The reducing ability becomes weaker while moving down the reactivity series.

The electropositivity of the elements decreases as we move down in the reactivity series of metals. All metals which are placed above hydrogen in the activity series can able to release hydrogen gas upon reacting with dilute HCl.

Therefore, the metals Iron, tin, and zinc release hydrogen gas when they react with the HCl. The order of reactivity is according to their reduction potential which is Zinc > iron > tin.

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Name the following ketone:
o
CH3CCH3

Answers

Answer: the answer is A

Explanation:

just finished this on acellus

Acetone is the name of the following compound and can also be referred to as 2-propanone.

What is a ketone?

ketone, any of a class of organic compounds characterized by the presence of a carbonyl group in which the carbon atom is covalently bonded to an oxygen atom.

Acetone, an organic compound, is chemically described as [tex]CH_3COCH_3[/tex], and can also be referred to as 2-propanone.

Acetone is a hydrocarbon derivative, more specifically a ketone in its simplest form because of its particular functional group.

Hence, acetone is the name of the following compound and can also be referred to as 2-propanone.

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...................................................

Answers

Explanation:

I honestly don't understand why you post useless questiond

How many Si atoms are there in 1.00 g of silicon

Answers

Number of atoms in 1 g of silicon are 6.022 * 10^23

calculate, a can of chicken broth contains 450 mg of sodium chloride in 240.0g of broth. What is the percent by mass of sodium chloride in the broth?

Answers

Answer:

The percent by mass of sodium chloride in the broth is 0.1875 %

Explanation:

Our first step is transforming the sodium chloride figure from mg to g

450mg x 1g/1000 mg= 0.45g

Now, we must calculate the percentage by using the following formula:

0.45g / 240g x 100= 0.1875%

Henceforth, we can conclude that the percentage by mass of sodium chloride in the broth is 0.1875%

The per cent by mass of sodium chloride in the broth is 0.1875 %

What is per cent by mass?

The mass per cent of a component of a compound is the percentage ratio of the mass of the component by the total mass of the compound. The formula is mass per cent = (mass of component / total mass of compound) × 100.

Given data:

Mass of sodium chloride =450 mg = 0.45g

Now, we must calculate the percentage by using the following formula:

[tex]\frac{0.45gX 100}{240g }[/tex]

= 0.1875%

Hence, we can conclude that the percentage by mass of sodium chloride in the broth is 0.1875%

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Which of these activities would a Forensic toxicologist NOT preform?

a. Determine the chemical
makeup of alcohol

b. Determine if drugs played a role in an accident.

c . Determine if drugs played a role in a perpetrator actions.

d. Determine if a person died of natural causes or a poison.

Answers

Answer:

A

Explanation:

because I know it from doing a test

What is the equilibrium constant K at 25°C for an electrochemical cell when E° = +0.0140 V and n = 2?(F = 96,500 J/(V・mol), R = 8.314 J/(mol・K))

Answers

The equilibrium constant of the electriochmeical cell as shown is  2.976.

What is the equilibrium constant?

The equilibrium constant of a reaction shows the extent of the conversion of the reactants to products.

Now we know that;

ΔG = -nFE°cell

n = 2

F = 96,500 J/(V・mol)

E°cell = +0.0140 V

ΔG = -(2 *  96,500  * 0.0140)

ΔG = -2702 J

But;

ΔG = -RTlnK

lnK = -(ΔG/RT)

K = e^[-(ΔG/RT))

K = e^[-(( -2702)/8.314 * 298]

K = 2.976

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Which of the following are true about photosynthesis and cellular respiration. (Select all that apply.)


The products of one process are the reactants of the other.


The relationship between them enables life to survive as we know it.


They both happen only in plants.


They both take place in human cells.

Answers

Answer:

2 and 4 are the best answers

Explanation:

Answer:

A and B

Explanation:

Took the k12 test.

If the actual yield for a substance is 39.487g but the theoretical yield is 38.000g, what is
the percent yield?
a. 2%
b. 96%
c. 50%
d. 104%

Answers

Answer:

b. 96%

Explanation:

8. Thermal Energy is?
A. Kinetic
B. Potential
c. Potential and Kinetic
D. Neither Potential and Kinetic

Answers

Thermal energy is the sum of the kinetic and potential energy of all the particles in an object. The figure shows that if either potential or kinetic energy increases, thermal energy increases.

hope it really helps...!!!

A lab technician determines the boiling point elevation of an aqueous solution of a nonvolatile, nonelectrolyte to be 1.12 C. What is the solution’s molality?

Answers

Answer:

2.19m

Explanation:

quizlet

is mixing water and glue a chemical or physical change?

Answers

Answer:

physical

Explanation:

because it would still remain as a liquid. if you were to add borax or something to it, then it would be a chemical change.

Determine the empirical formula of a compound containing 48.38 grams of carbon, 8.12 grams of hydrogen, and 53.5 grams of oxygen

Answers

As with most stoichiometry problems, it is necessary to work in moles. The ratio of the moles of each element will provide the ratio of the atoms of each element.

Get the mass of each element by assuming a certain overall mass for the sample (100 g is a good mass to assume when working with percentages).

Remeber that percentages are a ratio multiplied by 100. You must convert percentages back to their decimal value before working with them.

(.4838) (100 g) = 48.38 g C

(.0812 ) (100 g) = 8.12 g H

(.5350) (100 g) = 53.38 g O

Convert the mass of each element to moles of each element using the atomic masses.

(48.38 g C) (1 mol/ 12.10 g C) = 4.028 mol C

(8.12 g H) (1 mol/ 1.008 g H) = 8.056 mol H

(53.38 g O) (1 mol/ 16.00 g O) = 3.336 mol O

Find the ratio or the moles of each element by dividing the number of moles of each by the smallest number of moles.

Use the mole ratio to write the empirical formula.

Determine the longest wavelength of light required to remove an electron from a sample of potassium metal, if the binding energy for an electron in K is 1.76 × 103 kJ/mol. A. 113 nm B. 885 nm C. 68.0 nm D. 147 nm E. 387 nm

Answers

Answer:

The wavelength of light is 68 nm.

Explanation:

Given data:

Binding energy of electron = 176 × 10³ Kj/ mol or (1.76× 10⁶ j/mol)

Wavelength of light require to remove the electron = ?

Which unit is used to measure the distance between galaxies? Question 3 options: kilometers decades years light years

Answers

Answer:

light years

Explanation:

light year is the DISTANCE light travels in one year ...a very large distance

Answer:

light years

Explanation:

since distance between galaxy space ,objects .

Identify the type of energy conversion represented by each picture.
solar energy to light energy
electric energy to light energy
electric energy to heat energy
wind energy to electric energy

Answers

[tex]\qquad\qquad\huge\underline{{\sf Answer}}[/tex]

The given pictures show conversion of energy from one form to another.

#Picture 1

Electric energy to Heat energy

#Picture 2

Wind energy to electric energy

#Picture 3

Solar energy to light energy

#Picture 4

Electric energy to light energy

calculate the concentration of HCL

Answers

to find:

the concentration of HCI

solution:

[tex]mass \: formula \: of \: hci = 1 + 35.5[/tex]

[tex] = 36.5[/tex]

[tex]mass = relative \: formula \: mass \times amount[/tex]

[tex] = 36.5 \times 0.125[/tex]

[tex] = 4.56g | {dm}^{3} [/tex]

hence, the concentration of HCI is 4.56g/dm3.

Which mixture would be easiest to separate based on the size of the particles?
A.
oil and water
B.
vinegar and water
C.
sand and gravel
D.
sugar and water

Answers

Answer:

i believe sand and gravel because you can sift the sand

Explanation:

10. Boron has two naturally occurring isotopes, 10B with an atomic mass of 10.0129370amu and 11Bwith an atomic mass of 11.0093054amu. The atomic mass of boron is 10.81 (from the periodic table). The percent abundances of the boron isotopes are __________% 10Band __________% 11B.

Answers

Explanation:

allowing 20% discount on the market price of a watch the value of the watch will be rs 2376 when a VAT of 10% is added ,find it's market price

Which type of covalent bond is the least stable?
A.Covalent bonds
B.Double bonds
C.Single bonds
D.Triple Bonds

Answers

Answer:

D because: A Triple bond is when three pairs of electrons are shared between two atoms in a molecule. It is the least stable out of the three general types of covalent bonds.

What is the electrical conductivity of Copper and Glass?

Please help

Answers

Answer:

Table of Resistivity and Conductivity at 20°C

Material ρ (Ω•m) at 20 °C Resistivity σ (S/m) at 20 °C Conductivity

Deionized water 1.8×105 5.5×10−6

Glass 10×1010 to 10×1014 10−11 to 10−15

Explanation:

Table of Resistivity and Conductivity at 20°C

Material ρ (Ω•m) at 20 °C Resistivity σ (S/m) at 20 °C Conductivity

Deionized water 1.8×105 5.5×10−6

Glass 10×1010 to 10×1014 10−11 to 10−15

PLEASE QUICKLY HELP:)

which entry-level job would give you the best experience for a career in the lodging sector?

Choose one answer correctly!

A. Hostess
B. Réservation agent
C. Sever
D. Tour guide​

Answers

Answer:

i think Hostess but id K a lodging sector is an The hospitality industry encompasses a wide range of services and activities such as lodging, restaurants, food services, and convention centers. The lodging sector consists of hotels, motels, resorts, and bed and breakfasts.

Explanation:

HELP ME OUT PLS!!!!!!!!!

All stars begin their life in a

O black hole

O main sequence

O protostar

O nebula​

Answers

Answer:

nebula

Explanation:

I am well informed

the only solid figure that has two circular bases is a

Answers

Cylinder

Cylinder A cylinder is a solid figure with two parallel congruent circular bases.

Answer:

Cylinder

Explanation:

A cylinder is a solid figure with two parallel congruent circular bases.

Question 4 of 15
The types of radiation produced by alpha, beta, and gamma decay differ in
many ways. Which characteristic do they all have in common?
A. The ability to treat cancer
B. The ability to cause cancer
C. The ability to trace the movement of chemicals
D. The ability to damage human tissue

Answers

Answer:

D. The ability to damage human tissue

please give me brainliest.

A manometer measures 450 torr of pressure in a container with 0.500-L sample of carbon dioxide, CO2. The gas is compressed to a volume of 0.100 L. What is the new pressure reading in the manometer?

Answers

Let's see

Apply boyles law

P1V1=P2V2450(0.5)=0.1P_2225=0.1P_2P_2=2250Torr

Which types of particles are involved in a fission reaction?

A neutral neutron strikes a large neutral nucleus.

A positive proton strikes a large positive nucleus.

A neutral neutron strikes a large positive nucleus.

A positive proton strikes a large neutral nucleus.

Answers

The first one a neutral neutron strikes a large neutral nucleus

What is the molarity of a solution made by adding 1.565 moles of
PbNO3 to 0.500 L?
300. M
31.3 M
3.13 M
1.56 M

Answers

Answer:

3.13M

Explanation:

Using the Molaitry equation ( M = n/v ) just plug numbers in and solve.

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Which angle is coterminal with a 120 angle?A. An angle measuring 300B. An angle measuring-120C. An angle measuring 470D. An angle measuring 480 The cost proposed by the taxi company that charges $3 for the taxi drop plus $1.50 for each mile driven can be expressed as c=The cost proposed by the taxi company that charges $2 for the taxi drop plus $1.75 for each mile driven can be expressed as c= help me PLEASE, it's physical science D: The ________ is a Sumerian invention that helps determine the appropriate time for agricultural cultivation. Find the area of the shaded polygons. it has the diameters of 6, 8, 10. I WILL AWARD BRAINLIEST. PLS HELP ASAP I NEED THIS PLSSSS pls need help in math Prokaryotic DNA is:(Fill in the letters, this is for a crossword)_ e _ _ _ _ _ _ _ The Declaration of Independence includes the right __________.A) to use violent means to get the governments attentionB) to remove a government if it does not protect citizen's basic rightsC) of all men and women to elect their public officialsD) of all men and women to run for public office The man _who__ is wearing glasses is my uncles friend classify the underline word Listen to the following activities and write down how each individual in question just finished completing them. OJO! Be sure to start each sentence with a capital letter and end with a period Which verb form correctly completes the conversation?Andr: Tu aimes ce tableau?Gustave: Non. Parce que je ne ______ pas ce style.A. comprendB. comprennentC. comprendsD. comprenons Additional protections researchers can include in their practice to protect subject privacy and data confidentiality include: Hinduism was founded by How do you write thirteen and seventy-two hundredths as a decimal number? what was the relationship betwee the federal government government and economic growth in the aftermath of world war II He is running very well! I think he_______win! choice may/must/can't ? 9x + 5y = 352x + 5y = 0 Now I know this isnt social studies, but I need help!!Find the equation of an exponential function of the form y = ab* that passes through the points (3, 13.5) and (5,30.375). A cereal box is shaped like a rectangular prism. The box is 20 cm long by 5 cm wide by 30 cm high. What is the surface area of the cereal box? Help please. Its urgent. Right answer gets brainliest