It is found that after 24!hours 1/8 of the mass of a sample of a radio-active isotope remains What is the half-life of this isotope?

Answers

Answer 1

Answer:7.72 years

Nuclear half-life expresses the time required for half of a sample to undergo radioactive decay.

Explanation:

0.01 = 67.0 ×[tex](\frac{1}{2}) ^{\frac{98.0} {1/2 } }[/tex] [tex]\frac{0.01}{67.0}[/tex] = 0.000149=[tex](\frac{1}{2}) ^{\frac{98.0} {1/2 } }[/tex]

[tex]^{\frac{98.0} {1/2 } }[/tex] =log[tex]_{0.5}[/tex] (0.000149)=12.7

[tex]^{\frac{98.0} {1/2 } }[/tex]=7.72 years

Hope this helps have a great day/afternoon :)


Related Questions

(PLS HELP will mark brainliest!) Compare and contrast the alkali metals and the alkaline earth metals. Discuss their physical and chemical properties, their magnetic properties, and their electron configurations.

Answers

Answer:

I have a picture from my excerpt that basically answers all of that!

Hope it helps!

Explanation:

The attachment

The alkali metals and alkaline earth metals has different physical and chemical properties due to difference in their valence electrons.

Comparison of physical and chemical properties of alkali metals and the alkaline earth metals.                       Alkali Metals                             Alkaline earth metals

·Electronic      [Noble gas]ns1                                  [Noble gas]ns2

configuration

·Reactivity      Comparatively more reactive     Comparatively less

                                                                         reactive                        

·Hardness       Soft and can be cut by sharp     Comparatively harder

                      knife

·Valency         One valence electron               Two valence electron

·Ionic charge   +1                                              +2

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how much electrons are present in MnO4-

Answers

The correct answer is 5

In this simulation, you will be exploring the relationship between temperature and pressure while keeping volume
constant. Click here to begin. Select the Explore box. Answer the questions as you perform the steps.
1. Raise and push down the pressure pump handle to add gas molecules to the container. The initial temperature is
300 K (27º) and the pressure has a range of 5.4-6.2 atm. Notice the pressure values change as the particles
collide with the wall.
2. Click on the bucket to raise the temperature of the container to approximately 400 K (127°C). What happened to
the pressure?
Approximately what pressure range did you observe?
3. Click on the bucket to reduce the temperature to approximately 200 K (-73°C). What happened to the pressure?
Approximately what pressure did you observe?
4. What gas law mathematically shows the relationships between temperature and pressure?

Answers

Answer:

increased, 7.5-8.3 atm; decreased, 3.5-4.3 atm; Gay-Lussac's Law

Explanation:

1. The collision of gas molecules, results in the pressure increases.

2. The pressure of the system with an increase in the temperature has been 7.2-8.2 atm.

3. The pressure of the system with a decrease in the temperature has been 3.6-4.1 atm.

4. The relationship between the molecules has been given by Gay-Lussac's Law.

The relationship between the temperature and pressure has been given in the gaseous molecules with the ideal gas equation.

1. The temperature has been directly proportional to the temperature. Thus, with an increase in pressure, there has been an increase in temperature and vice versa.

With the collision of the gas molecules with the wall, there has been the liberation of the energy that increases the temperature. The increase in temperature mediates the increase in pressure.

Thus, with the collision of gas molecules, the pressure increases.

2. The relationship between the pressure and temperature has been given as:

[tex]\dfrac{P1}{T1}=\dfrac{P2}{T2}[/tex]

The initial temperature [tex]T1=300\;\text K[/tex]

Final temperature [tex]T2=400\;\text K[/tex]

Initial pressure, [tex]P1=5.4-6.2\;\text {atm}[/tex]

Final pressure, [tex]P2[/tex]

Substituting the values for calculating P2 as:

[tex]\rm \dfrac{5.4-6.2\;atm}{300\;K}=\dfrac{P2}{400\;K}\\\\\textit P2 = \dfrac{5.4-6.2\;atm}{300\;K}\;\times\;400\;K\\\\\textit{P}2=7.2-8.2\;atm[/tex]

The pressure of the system with an increase in the temperature has been 7.2-8.2 atm.

3. The pressure with the reduction of temperature has been given by :

[tex]\dfrac{P1}{T1}=\dfrac{P2}{T2}[/tex]

The initial temperature [tex]T1=400\;\text K[/tex]

Final temperature [tex]T2=200\;\text K[/tex]

Initial pressure, [tex]P1=7.2-8.2\;\text {atm}[/tex]

Final pressure, [tex]P2[/tex]

Substituting the values for calculating P2 as:

[tex]\rm \dfrac{7.2-8.2\;atm}{400\;K}=\dfrac{P2}{200\;K}\\\\\textit P2 = \dfrac{7.2-8.2\;atm}{400\;K}\;\times\;200\;K\\\\\textit{P}2=3.6-4.1\;atm[/tex]

The pressure of the system with a decrease in the temperature has been 3.6-4.1 atm.

4. The relationship between the molecules has been given by Gay-Lussac's Law. The law states that pressure has been directly proportional to the absolute temperature of the system.

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calculate the atomic mass of carbon if the two common isotopes of carbon have masses of 12.000 amu (98.89% abundance) and 13.003 amu (1.11% abundance)

Answers

12.01 amu

Work:

(12.000 × .9889) + (13.003 × .0111) = 12.01

turn the precents into decimals

Political considerations played a great role in the decision for the United States to enter the Space
Race.
True
False

Answers

True

The Cold War & tensions with Russia led to the great Space Race. Getting into space was a goal of the US as well as Russia and whomever got into space would be considered superior in the world's perspective

describe the relationship between the mass volume and density of material

Answers

Answer: For a given mass and volume, how much physical space a material takes up, of an object or substance, the density remains constant at a given temperature and pressure. The equation for this relationship is ρ = m / V in which ρ (rho) is density, m is mass and V is volume, making the density unit kg/m3.

Explanation:

Why does a planet stay in orbit?

Answers

Answer:

Gravity

Explanation:

A planet is gravitationally pulled around the sun.

Answer:

beause of gravitys pull and because the atmosphere of the beyond lol also bcs this i hope this helps your welcome boo >3

Explanation:

Newton realized that the reason the planets orbit the Sun is related to why objects fall to Earth when we drop them. The Sun's gravity pulls on the planets, just as Earth's gravity pulls down anything that is not held up by some other force and keeps you and me on the ground.

How many moles (of molecules or formula units) are in each sample?
A) 32.66 g CF2Cl2
B) 24.2 kg Fe (NO3) 2
C) 0.5912 g C8H18
D) 104 kg CaO
Express all answers to 4 sig figs

Answers

Answer:

A = 1.627 ×10²³ molecules of CF₂Cl₂.

B = 809.4 ×10²³ molecules of Fe(NO₃)₂.

C = 0.03117 ×10²³ molecules of C₈H₁₈.

D= 1116 ×10²³ molecules of CaO.

Explanation:

A)

Given data:

Mass of CF₂Cl₂ = 32.66 g

Number of moles = ?

Number of molecules = ?

Solution:

Number of moles = mass/ molar mass

Number of moles = 32.66 g/ 120.9 g/mol

Number of moles = 0.2701 mol

Number of molecules:

1 mole = 6.022×10²³ molecules

0.2701 mol×6.022×10²³ molecules / 1mol = 1.627 ×10²³ molecules of CF₂Cl₂.

B) Given data:

Mass of Fe(NO₃)₂ = 24.2 Kg  (24.2×1000 = 24200 g)

Number of moles = ?

Number of molecules = ?

Solution:

Number of moles = mass/ molar mass

Number of moles = 24200 g/ 180 g/mol

Number of moles = 134.4 mol

Number of molecules:

1 mole = 6.022×10²³ molecules

134.4 mol×6.022×10²³ molecules / 1mol =809.4 ×10²³ molecules of Fe(NO₃)₂.

C) Given data:

Mass of C₈H₁₈= 0.5912 g

Number of moles = ?

Number of molecules = ?

Solution:

Number of moles = mass/ molar mass

Number of moles = 0.5912 g/ 114.22 g/mol

Number of moles = 0.005176 mol

Number of molecules:

1 mole = 6.022×10²³ molecules

0.005176 mol×6.022×10²³ molecules / 1mol =0.03117 ×10²³ molecules of C₈H₁₈.

D) Given data:

Mass of CaO = 104 Kg  (104×1000 = 104,000 g)

Number of moles = ?

Number of molecules = ?

Solution:

Number of moles = mass/ molar mass

Number of moles = 104,000 g/ 56.1 g/mol

Number of moles = 1854 mol

Number of molecules:

1 mole = 6.022×10²³ molecules

1854 mol×6.022×10²³ molecules / 1mol = 1116 ×10²³ molecules of CaO.

If a boulder sits at rest on top of a mountain what conclusion can be made about the forces acting on the

Answers

A boulder sits at rest on top of a mountain. What conclusion can be made about the forces acting on the boulder? The forces acting on the boulder are balanced (net force equals zero).

If a boulder sits at rest on the top of the mountain , the forces acting on the boulder are zero as it is in the state of rest.

What is a force?

Force is defined as a cause which is capable of changing the motion of an object. It can cause an object which has mass to change it's velocity. It is also simply a push or a pull . It has both magnitude as well as direction.Hence, it is a vector quantity.

It has SI units of Newton and is represented by'F'.Newton's second law states that force which acts on an object is equal to momentum which changes with time. If mass of object is constant, acceleration is directly proportional to net force acting on an object.

The concepts which related to force are thrust and torque .Thrust increases the velocity of an object and torque produces change in rotational speed of an object.

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What is the charge of protons?

Answers

Answer:

protons naturally have the charge of +1

Answer:Protons have a positive electrical charge of one (+1) and a mass of 1 atomic mass unit (amu), which is about 1.67×10−27 kilograms

Explanation:

Does temperature have the same effect on gases as it does on liquids when it comes to viscosity? Explain.

When the temperature of a liquid (fluid) decreases, its viscosity increases. What happens to this fluid?

As the temperature of a liquid (fluid) increases, its viscosity decreases. What happens to this fluid?

Why does ketchup flow faster when heated?

Answers

Answer: Explanation:

With an increase in temperature, there is typically an increase in the molecular interchange as molecules move faster in higher temperatures. The gas viscosity will increase with temperature. ... With high temperatures, viscosity increases in gases and decreases in liquids, the drag force will do the same.

The increase in temperature causes the kinetic or thermal energy to increase and the molecules become more mobile. The attractive binding energy is reduced and therefore the viscosity is reduced.

liquids show a reduction in viscosity with increasing temperature. With high temperatures, viscosity increases in gases and decreases in liquids, the drag force will do the same.

Convert 0.0134 Liter to millimeter

Answers

Answer:

13400 millimeters.

Explanation:

Multiply the volume value by 1e+6

What is the volume of a box that has a length of 5 cm a width of 7 cm and a height of 9 cm

Answers

Answer:

V = L × w × h

V = 5 × 7 × 9

V = 315 cm³

The electronic structure of the atom X is : 2, 8, 1
A. In which group atom x is found:—————-
B. In which period atom x is found:—————
C. What is the name of atom x:———————-

Answers

Answer:

A. grou(I)

B. 3rd period

C. Sodium (Na)

Explanation:

it belongs to group (I) since it has one valence electron

it belongs to 3rd period since it has three energy levels

What would pressure be if volume was 0

Answers

Answer:

The lower the temperature, the lower the pressure inside of the sphere. If the exact values were plotted out, a linear relationship would be apparent. Extrapolating this line to the point where there would be no pressure yields absolute zero, which is about -273.15 degrees Celsius.

Explanation:

how many grams of oxygen gas are produced when this sample is heated?

Answers

Answer:  2.92%

Explanation:

Is 2.92% which I clearly believe

1. In part 1, you collected data about how the amount of sugar affects the amount of gas produced. Analyze those data and draw a conclusion. (16 points) a. What gas inflated the balloons? (2 points)​

Answers

Answer:

carbohydrate is an essential biomolecule so the affect of suger fluctuates when enzyme consumes the substrates of glucose molecules

Which of the following is NOT an example of a homogeneous mixture? a oxygen b tea c water d pizza

Answers

pizza because the ingredients arent mixed together completely. you can clearly see the different ingredients as compared to the others

What does a subscript indicate in a chemical formula?

A. The number of atoms of that element in the molecule

B. The number of bonds that element forms in the molecule

C. The position in the molecule that element occupies

D. The atomic number of the element in the molecule

Answers

A the number of atoms of that element in the molecule

Answer:

The number of atoms of that element in the molecule

Explanation:

You're welcome

Liquids will boil at a higher temperature when they are at a lower elevation true or false ?

Answers

Question: Liquids will boil at a higher temperature when they are at a lower elevation true or false ?

Answer: True






Which of these would have particles with the highest kinetic energy?

ice
water
water vapor

Answers

Answer:

water vapor

Explanation:

because gas molecules moves the fastest

Answer:

water vapor

Explanation:

Liquid water molecules have less freedom to move around. While molecules of water vapour have more freedom to move around as there is larger space between the molecules. Hence, the kinetic energy of water molecules is more as compared to the kinetic energy of liquid water

When Silver (Ag) forms a metallic bond with other Silver atoms, what do the valence electrons move into? A. the all go to the same Silver atom B. the bond with the oxygen in the atomsphere C. they escape to free space D. the sea of electrons

Answers

Answer:

D. the sea of electrons

Explanation:

Metallic bonds are defined as the bonds formed between two or more metals. Silver atom form metallic bond with other silver atoms.

In metallic bond, the free electrons or valence electrons present in s and p orbitals delocalize. The valence electrons do not move around the atoms or enter the atoms whereas they form a sea of electrons in which they surround the nuclei (positively charged) of the metal ions interacting. The valence electrons are then freely move in the space between the atomic nuclei.

Hence, the correct answer is "D. the sea of electrons".

1. Which family of elements is most likely to lose electrons?
2. Which family of elements is most likely to gain electrons?

Answers

Answer:

Elements that are metals tend to lose electrons and become positively charged ions called cations.

Elements that are nonmetals tend to gain electrons and become negatively charged ions called anions.

Hope it helps:)

Metal are the  family of elements which is most likely to lose electrons. Non metals are the  family of elements which is most likely to gain electrons.

What is element?

The quantity of protons an element has defines it. An element's atoms all contain the same amount of protons, but its electron and neutron counts might vary. Ions are produced by altering the electron to proton ratio, whereas isotopes are produced by altering the neutron count.

118 known elements are present. A study is being done to create element 120.1. The periodic table will have to be modified to include element 120 after it has been created and validated. Metal are the  family of elements which is most likely to lose electrons.

Therefore,  metal are the  family of elements which is most likely to lose electrons.

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Find the area of a rectangle with a length of 10cm and a width of 7cm.

A.70cm
B.17 cm
C.17cm2
D.70cm2

Answers

Answer:

D

Explanation:

You would do 10*7 witch would be 70 then cm2 so the answer is 70cm2

The answer to your question is D so 70cm2 good luck


Help please I’ll make you as brainlister 3

Answers

Answer: C. Al (aluminum)
Explanation: it has 3 valence electrons :)

Answer:

It doesn't look like any of them but the best answer is SI

Explanation:

the human eye has three types of cones cells. damage to any one of the types of cone cells doesn't cause total blindness because of the
A. presence of rod cells
B. other two functional Cone cells
C. presence of optic nerves

Answers

they have rod cells - this helps them be able to see colors through a spectrrum located in the retina

what happens to the pen?what could have caused the pen's motion?

grade 8 asap

Answers

Answer:

One is tension force that acts on the string and the other one is gravitational force that is acting on the pen and is therefore, the one that pulls the pen towards the ground. Therefore, the pen's motion is caused by the unbalanced force acting on the pen.

7. Electrons that are free to move in a metal are referred to as ________ electrons.
A.magnetic
B.valence
C.electrostatic
D.cation

Answers

Answer:

D; Cation

They are the valence electrons that can move between two metal molecules.

Explain how the mid-ocean ridge supports
the theory of sea floor spreading.
help plzzz:(

Answers

the ridge of mid ocean b is the answer hope this helps

A hypothesis is ______ to explain a set of observations.

1 one possible way
2 the correct method
3 a factual statement
4 a set of data ​

Answers

Answer:

1

Explanation:

one possible way its just a theory of what the answer could be

Answer:

3-a factual statement

Explanation:

A hypothesis is a factual statement to explain a set of observations.

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Read the passage. First,identify two themes,Then, identify the evidence from the passage that best supports each theme.Now that Mia was a seventh grader, she could officially try out for the swim team. Mia didn't have much experience, but she had always dreamed of being a swimmer. Tryout week arrived, and Mia did her best. However, at the end of the week, she didn't find her name on the team roster. Disappointed, she went home and told her mother the news. "Mia, you can be whatever you want, but you need to remember that it will always take hard work," her mom reminded her. Mia dried her tears and made a plan. After a full year of dedicated practice, including several early-morning swim sessions each week, Mia tried out once again. This time, the roster proudly displayed her name as a new member of the swim team. A single phase, 50-KVA, 2400-240-volt, 60 Hz distribution transformer has the following parameters: Resistance of the 2400-volt winding Ri=0.75 ohm Resistance of the 240-volt winding R=0.0075 ohm Leakage reactance of the 2400-volt winding X:=1 ohm Leakage reactance of the 240-volt winding X2=0.01 ohm Core loss resistance on the 2400 side Rc=733.5 ohms Magnetizing reactance on the 2400 side X=4890 ohms a. Draw the equivalent circuit referred to the high voltage side and referred to the low- voltage side. Label the impedances numerically. b. The transformer is used as a step-down transformer at the load end of a feeder having impedance of (0.5+j2.0) ohms. Determine the voltage V. at the ending end of the feeder when the transformer delivers rated load at rated secondary voltage and 0.8 laggin power factor. Neglect the "exciting current" l. of the transformer (this is the current into the parallel Rc/jXm combination), which is another way of saying that you should use what we called in class the "approximate circuit #2). Find the difference: 4.203 - 0.01 A line contains the points (82, 96) and (87, 86).What is the slope of the line in simplified form?Enter your answer in the box. PLEASE HELP!! I NEED TO FINISH THIS NOW!! 13 POINTS! PLEASE ANSWER QUICKLY AND CORRECTLY AND PLEASE EXPLAIN YOUR ANSWER IN ORDER TO RECEIVE BRAINLIEST!!!The primary purpose of the political pamphlet Common Sense, by Thomas Paine, was to A. show the British public that the American colonists had a powerful armyB. point out weaknesses in the Articles of ConfederationC. lift American spirits after a series of military defeatsD. persuade colonists to support the cause of American independence what is the product of -3 1/4 and -1 1/2 help meeeee.......... What is the slope of the line? how many grams of oxygen gas are produced when this sample is heated? Determine the x-intercept of theequation below. Write your answer asan ordered pair.-3x + 5y = 15 What type of bond is present between two atoms of zinc in a nickel Solve [tex]x^{3}[/tex] = 64. Surrealists are known for their:a. love of morningb. innovative quilting techniques.C. dreamy or fantastic imagery.d. large familiesfree brainliest for a correct answer :) Realiza una carta dirgida una persona q haya afrontado positivamente la pandemia Question 4 of 10Which of these is not a function of some membrane proteins?O A. Catalyzing chemical reactions in the cellB. Receiving messages from other cellsC. Recognizing other types of cellsO D. Keeping polar molecules out of the cell Does a parallelogram have to have equal sides brainliest for correct answers What are the pieces of evidence that the author uses to support his main ideas? Should we as a country celebrate the Fourth of July in the United States, or is it, as Frederick Douglass claimed, a "sham" to black people in the United States? Discuss your opinion and explain, using personal examples what is 4 to the power of 4 The adjusted trial balance of Dawson Company contained the following information. Assume the tax rate is 33%: Debit Credit Sales revenue $425,000Sales returns and allowances $ 20,000Sales discounts 5,000Cost of goods sold 300,000Operating expenses 61,000Interest revenue 2,000Interest expense 1,000Compute the gross profit. rate(%)