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

I NEED HELP WITH THIS ASAP!!!!!!!!!!!!!

Which chemical equation best represents the Law of Conservation of
Mass?
A. H+0 -> H20
B. H2 + 02 --> H20
C. 2H2 + 02 --> 2H,0
D. H2 + 02 --> 2H,02

Answers

Answer: The answer is B

Explanation:

Which of these processes are chemical reactions? Type the correct answer in each box.
Boiling an egg
Crushing spices
veges rotting
chopping veges
dew forming

Answers

boiling an egg

hope this helps

Zinc has an average atomic mass of 65.37 amu. Jack is trying to figure out what the most abundant isotope of zinc is, but he doesn't have access to the internet, so the average atomic mass is the only information he has. Jack decides to made an educated guess as to the most abundant isotope of zinc by assuming there are only two isotopes of zinc. If Jack assumes there are only two isotopes of Zn, what he be most likely to decide is zinc's most abundant isotope?
Question 5 options:

Zinc-64


Zinc-65


Zinc-68


Zinc-66

Answers

Zinc's most abundant isotope : Zinc-65

Further explanation

Isotopes are atoms whose no-atom has the same number of protons while still having a different number of neutrons.

So Isotopes are elements that have the same Atomic Number (Proton)

Atomic mass is the average atomic mass of all its isotopes

In determining the mass of an atom, as a standard is the mass of 1 carbon-12 atom whose mass is 12 amu

Mass atom X = mass isotope 1 . % + mass isotope 2.%

To decide zinc's most abundant isotope, then choose the closest mass number

or we can check the difference with the average mass number, if the value is the smallest, then that isotope has the largest abundant

Zinc-64

[tex]\tt \dfrac{65.37-64}{65.37}=0.021[/tex]

Zinc-65

[tex]\tt \dfrac{65.37-65}{65.37}=0.005[/tex]

Zinc-68

[tex]\tt \dfrac{68-65.37}{65.37}=0.04[/tex]

Zinc-66

[tex]\tt \dfrac{66-65.37}{65.37}=0.009[/tex]

The closest = Zinc-65(the smallest)

can someone explain what radioisotopes are?

Answers

Answer:

A radioisotope is a radioactive isotope.

Explanation:

On the Periodic Table, elements 92 and up are radioactive. So that is Uranium and any higher elements. Remember that radioactive elements love to decay and are dangerous.

Isotopes are different forms of an element. For instance, we could have different amount of neutrons in the same element (same number of protons).

We could have an element like He - 4 vs. He - 6, where He - 4 would have 2 neutrons and He - 6 would have 4 neutrons.

So a radioisotope would be an elemental isotope that is radioactive. A good example of this is Uranium.

We have thousands of different isotopes of Uranium, but 2 are well known: Uranium - 235 and Uranium - 238. Both are the same element with the same amount of protons, but both have a different amount of neutrons.

What is the activation energy of a reaction?

Answers

Answer:

The activation energy for the forward reaction is the amount of free energy that must be added to go from the energy level of the reactants to the energy level of the transition state. ... Once a reactant molecule absorbs enough energy to reach the transition state, it can proceed through the remainder of the reaction.

Explanation:

Answer: Activation energy is how much energy it takes for a reaction to occur.

Explanation:

A procedure calls for 0.250 kg of sugar. Your balance is in ounces. What mass in ounces should be weighed out on this balance?

Answers

Answer:

8.81849

Explanation:

i believe the whole number would be this but usually i round to the second decimal point, i dont know if you could do that in chemistry tho

PLEASE SOMEONE HELPP

Answers

Answer:

D

Explanation:

3. compounds in which elements are held together by covalent bonds...keeps their own properties
A polar molecule
B. element
C. compound
D. molecule

Answers

The anserr is c that what i think

what is the central dogma of biology? QUICK PLEASE

Answers

Answer:

The central dogma states that the pattern of information that occurs most frequently in our cells is: From existing DNA to make new DNA (DNA replication?) From DNA to make new RNA (transcription) From RNA to make new proteins (translation).

Explanation:

Which sublevel comes after 4d orbital

Answers

Answer:

5s

Explanation:

The 4d sublevel is filled next, after the 5s sublevel.

Describe the three phases of matter (solid, liquid, and gas) in terms of particle spacing, ability to fill shape and volume of container, energy of particles , and strength of intermolecular forces

Answers

Answer: solids are tense but spread out. Gas is spread out completely and liquid is all together

Explanation:

Which is a homogenous mixture?


1. ceasar salad

2. pre-cooked pizza

3. coffee in a cup

4. different color beads in a bowl

Answers

Answer:

ceasar said is a homogeneous mixture

Answer:

ceasar salad

A glass of milk occupies a volume of 50.0 mL and has a mass of 52.0. what is its density

Answers

Answer: 1.04 is the density.                   Explanation: Just like a solid, the density of a liquid equals the mass of the liquid divided by its volume; D = m/v.    52.0/50.0=

In dilute aqueous solution, as [H+] increases:
A. pH decreases
B. pOH increases
C. [OH-] decreases

Answers

Answer:

B

Explanation:

The answer is B, I hope this helps you!

A student mixed several different 12 mm plastic beads together by mistake. Luckily the beads had different densities. One group of beads had a density of 0.6 g/cm3; the other beads had a density of 1.2 g/ cm3. Describe a method the student can use to sort the beads.

Answers

Answer:

The answer is "Each student will get a glass of water and drop the bead into it  but the beads float 0.6 g / cm3 and slip down to 1.2 g / cm3

".

Explanation:

One's masses would've been dissimilar, even though their width and concentrations were also equal. Whenever the type-A mass is m,  then the type-B mass is 2 m. One should measure then, therefore.  

Water has a 1g / cm^3 density. Although Type A is higher than air, Type B is much more compact. it means will float if they place  it in water type-A where type-B sinks.

Ribosomes are cell structures that make

Answers

Ribosomes link amino acids together in the order specified by the codons of messenger RNA (mRNA) molecules to form polypeptide chains.

Ribosomes are cell structures that make protein. They are the primary site of the synthesis of protein. They are made up of protein and RNA.

What are ribosomes?

Ribosomes are cell organelles scattered in the cytoplasm of the cell. They are tiny and round vesicles. They are present in both prokaryotic and eukaryotic cells. Furthermore, they are present freely in the cytoplasm. Ribosomes are also present near the endoplasmic reticulum.

Ribosomes are made up of RNA and protein, and they synthesize the protein in the cell. Ribosomes read the mRNA and by these codes of mRNA, it constitutes amino acids, that grow into a long chain of the protein.

Thus, ribosomes are the parts of cells that produce protein. They serve as the central location for protein production. They are composed of RNA and protein.

To learn more about ribosomes, refer to the link:

https://brainly.com/question/241631

#SPJ6

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

If anyone have the answers to this plz tell me

Answers

Explanation:

hey can I please get the passage so that I can help you

Problem Page Decide whether these proposed Lewis structures are reasonable. proposed Lewis structure Is the proposed Lewis structure reasonable? Yes. No, it has the wrong number of valence electrons. The correct number is: No, it has the right number of valence electrons but doesn't satisfy the octet rule. The symbols of the problem atoms are:* Yes. No, it has the wrong number of valence electrons. The correct number is: No, it has the right number of valence electrons but doesn't satisfy the octet rule. The symbols of the problem atoms are:*

Answers

The question is incomplete, the complete question is shown in the image attached.

Answer:

1) No, it has the right number of valence electrons but does not satisfy the octet rule.

2) Yes

3) No, it has the wrong number of valence electrons, the correct number is 16

Explanation:

If we look at the first structure in the image(HCN), it easy to see from inspection that nitrogen has three valence electrons as it is normally supposed to have. However, if we count all the electrons around nitrogen, we will notice that they are six instead of eight. Thus nitrogen has not satisfied the octet rule here.

The structure HBr satisfies the octet rule, hence it is a reasonable Lewis structures for the compound shown.

CO2 has 16 valence electrons but the structure shown contains about 20 valence electrons hence it is not a reasonable Lewis structure for the compound.

Yes, in HCO⁺ the proposed lewis structure is reasonable.

No, COCl₂ has the wrong number of valence electrons.

No, OH⁻ has the right valence electron but does not obey the octet rule.

The correct structure for the question can be seen in the image attached below.

In the proposed structure, the number of valence electrons in HCO⁺ is: ( 1 + 4 + (6-1) ) = 10e⁻

Thus, the atoms obey the octet rule and the number of calculated valence electrons corresponds with what we have in the given structure.

Yes, the structure is correct and reasonable.

In COCl₂, the central carbon bonding to the oxygen is supposed to be doubly bonded and not singly bonded.the number of valence electron in COCl₂ is: ( 4 + 6 + (7 × 2)) = 24e⁻

The calculated number of valence electrons is different from the given structure of 26e⁻, so we can say No, it has a wrong number of valence electrons.

In the third structure, oxygen is supposed to have three lone pairs of electrons in order to obey the octet rule.the number of valence electrons in the structure is: (6 + (1+1) = 8e⁻

But both H, as well as, O do not obey the octet rule. Therefore, we say No, it has the right number of valence electron but do not obey the octet rule.

Learn more about valence electrons here:

https://brainly.com/question/12717954?referrer=searchResults

Which noble gases is closest to magnesium? On the periodic table? What must happen if a magnesium atom for it to have an electron arrangement similar to that of a noble gas?

Answers

Answer:

Neon and loose electrons

Explanation:

Magnesium has an electron configuration of 2e 8e 2e, and Neon is 2e,8e. For Mg to have a similar electron arrangement it must loose its two valence electrons and make it an ion.

Answer:

Noble neon gas is the closest.

Explanation:

noble Neon  gas

The Magnesium would have to lose two electrons

QUESTION 2: How is velocity different from speed? *
1 point
Velocity is when an object goes in reverse
Velocity is the direction an object moves in, and it has nothing to do with speed
Velocity is speed and direction together

Answers

Answer:

Speed is the rate at which an object covers distance.

Velocity is the speed of something in a given direction.

A sample of gas has a volume of 526 mL at 346 mmHg and 35.0°C. Determine the moles of gas.​

Answers

Answer:

The moles of gas is 0.009474 moles.

Explanation:

Given that,

Volume = 526 mL

Pressure = 346 mmHg

Temperature = 35.0°C

We need to calculate the moles of gas

Using formula of ideal gas

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

Where, P = pressure

V = volume

R = gas constant

T = temperature

Put the value into the formula

[tex]n=\dfrac{\dfrac{346}{760}\times0.526}{0.08206\times(35+273)}[/tex]

[tex]n=0.009474\ moles[/tex]

Hence, The moles of gas is 0.009474 moles.

ito ang kontinenteng nagtataglay ng pinakamaraming bansa sa lahat ng kontinente​

Answers

Answer:

Africa

Explanation:

Ang Africa ay ang kontinente na mayroong pinakamataas na bilang ng mga bansa sa lahat ng mga kontinente.

Kasalukuyan, ang bilang ng mga bansa sa kontinente ay 54, ito ay 53 bago ang South Sudan ang pinakabagong sumali.

Ang bilang na ito ay pinaniniwalaang tataas sa mga darating na taon dahil sa kaguluhan ng iba't ibang mga segment sa ilang mga bansa para sa kalayaan

POSSIBLE POINTS: 26.67
Match the seasons for the Northern Hemisphere, Winter, Spring Summer, Fall to the different points on the diagram

Answers

Answer:

vv

Explanation:

Point A: Summer

Point B: Fall

Point C: Winter

Point D: Spring

Match each label below with the appropriate term. Note: there may be more than one correct answer.

nonbonding electrons
sigma bond
represents two electrons

Answers

Answer: sigma bond

Represents two electrons

Explanation:

E2020

Answer:

Sigma Bond AND Represents two electrons.

Explanation:

Trillions of cells join together to form ?

Answers

Answer: you like your body and tissue and organs and stuff

Explanation: it takes so much cells because of them being so small but with out them we would not be at all the same

In what type of inheritance do you see both traits on the same individual, but not
blended?
a. Incomplete Dominance
b. Codominance
c. Both
d. Neither

Answers

B. Codominance .....

What is often added to the water used when reacting the group 1 metals with
water?
Universal indicator
An acid
An alkali
Oil
What is produced when sodium reacts with water?
Sodium oxide and water

Answers

Answer:

an acid.

sodium oxide and water

The number of yeast cells in a laboratory culture increases rapidly initially but levels off eventually. The population is modeled by the function а n = f(t) = 1 + be-0.90 where t is measured in hours. At time t = 0 the population is 30 cells and is increasing at a rate of 24 cells/hour. Find the values of a and b. a = b = According to this model, what happens to the yeast population in the long run? O The yeast population will shrink to 0 cells. The yeast population will stabilize at 270 cells. The yeast population will stabilize at 135 cells. The yeast population will stabilize at 8 cells. O The yeast population will grow without bound.

Answers

Answer:

Explanation:

[tex]n=f(t)= \frac{a}{(1+be^{-.9t})}[/tex]

At t = 0

30 =  [tex]\frac{a}{1 + b }[/tex]

30 + 30 b = a

 [tex]\frac{dn}{dt} =f(t)= \frac{-.9abe^{-.9t}}{(1+be^{-.9t})^2}[/tex]

For t = o

[tex]\frac{dn}{dt} =f(t)= \frac{.9ab}{(1+b)^2}[/tex]

given

24 = [tex]\frac{.9ab}{(1+b)^2}[/tex]

24 = [tex]\frac{30\times.9b }{1+b}[/tex]

24 = 27b / 1 + b

24 + 24 b = 27 b

24 = 3 b

b = 8

a = 30 + 30 x 8 = 270

[tex]n=f(t)= \frac{a}{(1+be^{-.9t})}[/tex]

Put t = infinity

n = a = 270

So at infinite time yeast population will stabilise at number 270 .

The layer of skin that forms the fingerprint is called the

Answers

Answer:

Explanation:

The fingerprints are produced from a layer in the skin called the papillary layer, which is a layer within the dermis layer of skin. It produces an extra thick layer to form the ridges of fingerprints.

Answer:

Dermis

Explanation:

The inner layer of skin is called the dermis. It is thicker and provides the protection and support that the skin provides the body. The two layers are separated by the basement membrane. Fingerprints are produced by the epidermis.

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