# If An Isotope Has A Half-Life Of 4 Billion Years, Then In 4 Billion Years What Will Happen?

Contents

## What isotope has a half-life of 4.5 billion years?

Uranium-238

Parent Isotope Stable Daughter Product Currently Accepted Half-Life Values
Rubidium-87 Strontium-87 48.8 billion years

## What percent of parent isotope would remain after 4 half lives?

62.5 g

After 4 half-lives (2000 years) 62.5 g of the parent isotope will remain. After 5 half-lives (2500 years) 31.25 g of the parent isotope will remain. After 6 half-lives (3000 years) 15.625 g of the parent isotope will remain.

## What is the half-life of uranium 235?

The half-life of uranium-238 is about 4.5 billion years uranium-235 about 700 million years and uranium-234 about 25 thousand years.

## What percentage remains after 4 half-lives?

After 4 half-lives there will be 6.25% of the original isotope and 93.75% of the decay product.

## When 4 half-lives have gone by what percent of the original parent product still remains in a rock?

A rock is dated using K-40. After 5 half-lives what percent of parent and daughter isotopes are present in the rock sample? 7. A rock is found to be 2.84 billion years old using U-235 dating.

KEY: Half-Life Calculations.
Element Uranium U-238 Pb-206 (Lead) 4.5 billion years

## What parent isotopes could be used to date a rock that is 4 billion years old?

Two isotopes of uranium are used for radiometric dating. Uranium-238 decays to form lead-206 with a half-life of 4.47 billion years. Uranium-235 decays to form lead-207 with a half-life of 704 million years. Uranium-lead dating is usually performed on crystals of the mineral zircon (Figure 11.26).

## What is the formula for half-life in chemistry?

The half-life of a reaction is the time required for the reactant concentration to decrease to one-half its initial value. The half-life of a first-order reaction is a constant that is related to the rate constant for the reaction: t1/2 = 0.693/k.

## What is the half-life formula calculus?

ln 2 k

Definition. Half-life = ln 2 k . Half-life = ln 2 k .

## What is half-life of isotope?

one-half
The half-life of a radioactive isotope is the amount of time it takes for one-half of the radioactive isotope to decay. The half-life of a specific radioactive isotope is constant it is unaffected by conditions and is independent of the initial amount of that isotope. Consider the following example.Jul 31 2021

## What determines half-life?

A ‘half-life’ is defined as the amount of time taken for the number of nuclei present in a sample at a given time to exactly halve. This value does not depend on the moment chosen: the amount of time taken for the nuclei to halve will always be the same.

## What is an isotope half-life quizlet?

definition of half life. the time taken for the radioactivity of a specified isotope to fall to half its original value. a half life of a radioactive substance is. the time it takes to get half its radioactivity to go away.

## What is Half-Life in nuclear physics?

Half-life (symbol t12) is the time required for a quantity to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable atoms survive.

## What is the nuclear equation?

Nuclear equations represent the reactants and products in radioactive decay nuclear fission or nuclear fusion. Instead of chemical equations where it shows the different number of elements is conserved in a reaction in a nuclear reaction the atomic mass and proton number are conserved.

## What is the formula for uranium-235?

Uranium-235 Symbol

The symbol or formula for this radioactive isotope is 235U. It is also denoted by U-235.

## What is the half life of uranium 237?

6.75 days

Uranium
Mass Number Half-life Decay Mode
237 6.75 days Beta-minus Decay
238 4.468×10 9 years Spontaneous Fission
Alpha Decay
239 23.45 minutes Beta-minus Decay

## What does the 235 represent in uranium-235 quizlet?

In terms of protons neutrons and electrons what does the 235 mean? Uranium atom contains 92 protons in the nucleus. Why is uranium-235 an ideal isotope to use for nuclear technology compared to something like carbon-12? It Contains a large nucleus that can be split when truck by fast moving neutron.

## What percent of the parent isotope remains after 2 half-lives?

After two half-lives 75% of the original parent atoms have been transformed into daughter products (thus only 25% of the original parent atoms remain). After three half-lives only 12.5% of the original parent atoms remain. As more half-lives pass the number of parent atoms remaining approaches zero.

## What fraction of a radioactive isotope remains after 4 half-lives have occurred?

10.3: Half-Life
Number of Half-Lives Passed Fraction Remaining Percentage Remaining
2 1/4 25
3 1/8 12.5
4 1/16 6.25
5 1/32 3.125

## How many half-lives have passed if a substance is left with 3.125 percent of the original amount?

5 half lives

Explain. Isotope A : P=3.125% so 5 half lives have passed.

## How many half-lives have passed if a rock contains 25% parent isotopes and 75% daughter isotopes?

two half-lives

If a rock contains 25 percent of a parent isotope and 75 percent of its daughter isotope two half-lives must have passed.

## How many half-life periods have passed if a fossil contains 1/32 of the original amount of carbon 14?

5 half lifes

Explanation: 132=125 so the fossil has aged for 5 half lifes.

## What would you expect the half-life of the isotope used to date the age of Earth at 4.6 billion years to be?

Two uranium isotopes are used for radiometric dating. Uranium-238 decays to lead-206 with a half-life of 4.47 billion years.

## What is the parent to daughter isotope ratio of 1 half-life has passed?

1:1
The ratio of parent to daughter after one half-life will be 1:1. After two half-lives half of the remaining half will decay leaving one-quarter of the original radioactive parent atoms. Those transformed atoms bring the tally of daughter atoms to three-quarters of the crop of parent plus daughter atoms.

## When should a long half-life versus a short half-life isotope be used for dating?

Radioisotopes with longer half-lives are used to date older specimens and those with shorter half-lives are used to date younger ones. Carbon-14 dating is used to date specimens younger than about 60 000 years old. It is commonly used to date fossils of living things and human artifacts.

## What is a half-life in math?

Half-life is defined as the amount of time it takes a given quantity to decrease to half of its initial value. The term is most commonly used in relation to atoms undergoing radioactive decay but can be used to describe other types of decay whether exponential or not.

## What isotope has the shortest half-life?

Hydrogen-7 ( about 23x10E-24) has the shortest half life.