If the half-life of an unstable isotope is 10,000 years, and only 1/8 of the radioactive parent remains in a sample, how old is the sample?

Answers

Answer 1

Answer: Have in mind that a radioactive half-life is the amount of time it takes for half of a sample to decay. So, if the amount remaining after x half-lives is (1/2)↑x times the amount you started with. So for 1/18 of radioactive parent then (1/2)↑6 equals 30,000 years

Answer 2

Answer:

Answer: 30,000

Explanation: I'm taking gradpoint

Related Questions

Which pair below describes isotopes of the same element? A) an atom with 6 protons and 8 neutrons - an atom with 8 protons and 6 neutrons B) an atom with 6 protons and 6 neutrons - an atom with 6 protons and 7 neutrons C) an atom with 8 protons and 8 neutrons - an atom with 7 protons and 8 neutrons D) an atom with 7 protons and 6 neutrons - an atom with 6 protons and 6 neutrons
Na2S2O3 + KBrO3 + H2SO4 = Na2S4O6 + K2SO4 + Na2SO4 + Br2 + H2O
What ion do acids release in solution?
A test tube containing CaCO₃ is heated until the entire compound decomposes. If the test tube plus calcium carbonate originally weighed 30.08 grams and the loss of mass during the experiment was 4.40 grams, what was the approximate mass of the empty test tube?A. 20.08 g B. 21.00 g C. 24.50 g D. 25.08 g E. 25.68 g Can anyone explain this one for me?
Why is the reaction of Iron and hydrochloric acid slow

Which is a redox reaction?A) 2KBr + F2 ---> 2KF + Br2
B) 2HCL + Mg(OH)2 --> 2HOH + MgCl2
C) 2NaCl + H2SO4 --> Na2SO4 + 2HCl
D) Ca(OH)2 + Pb(NO3)2 --> Ca(NO3)2 + Pb(OH)2

I know the answer is A, but confused as to why that is. Can someone explain this for me? Thanks.

Answers

You have to look at the oxidation states of each atom in the reaction. Since redox reactions involve the transfer of electrons from one element to another, 2 elements need to have oxidation state changes.
option a is the only option that has a change in oxidation sates. Fluorine goes from 0 to -1 indicating that it gained electrons (got reduced) while bromine goes from -1 to 0 indicating it loses electrons (got oxidized).
(2Br⁻→Br₂+2e⁻ and F₂+2e⁻→2F⁻).

I hope this helps. Let me know if anything is unclear.

Which element has 32 protons in its nucleus? phosphorus cobalt germanium sulfur

Answers

Answer:

Germanium.

Explanation:

In a neutral atom: the number of protons = the number of electrons.

Atomic number of a neutral atom = number of electrons = number of protons.

Phosphorous is an element with atomic number 15 and thus contains 15 electrons and 15 protons.

Cobalt is an element with atomic number 27 and thus contains 27 electrons and 27 protons.

Germanium is an element with atomic number 32 and thus contains 32 electrons and 32 protons.

Sulfur is an element with atomic number 16 and thus contains 16 electrons and 16 protons.

The element that has 32 protons in its nucleus is Germanium.

What is the half-life of a radioisotope if 25.0 grams of an original 200.-gram sample of the isotope remains unchanged after 11.46 days?(1) 2.87 d (3) 11.46 d
(2) 3.82 d (4) 34.38 d

Answers

Answer : The correct option is, (2) 3.82 d

Solution : Given,

As we know that the radioactive decays follow first order kinetics.

So, the expression for rate law for first order kinetics is given by :

$k=(2.303)/(t)\log(a)/(a-x)$

where,

k = rate constant

t = time taken for decay process = 11.46 days

a = initial amount of the reactant = 200 g

a - x = amount left after decay process = 25 g

Putting values in above equation, we get the value of rate constant.

$k=(2.303)/(11.46)\log(200)/(25)=0.1814$

Now we have to calculate the half life of a radioisotope.

Formula used : $t_(1/2)=(0.693)/(k)$

Putting value of 'k' in this formula, we get the half life.

$t_(1/2)=(0.693)/(0.1814)=3.820$

Therefore, the half-life of a radioisotope is, 3.820 d

1. 200/2=100. 100/2=50. 50/2=25. So that's 3 to get to 25.

2. 11.46/3=3.82

The answer is (2).

Predict whether a reaction will occur when HClO and Sr(OH)2 solutions are mixed, if yes determine spectator ions in the ionic equation.

Answers

Answer:

$ClO^-\n\nSr^(2+)$

Explanation:

Hello there!

In this case, according to the reaction between hypochlorous acid and strontium hydroxide which yields stontium hypochlorite and water as a neutralization reaction:

$2HClO(aq)+Sr(OH)_2(aq)\rightarrow Sr(ClO)_2(aq)+2H_2O(l)$

Thus, since HClO is a weak acid, it is not fully ionized so the complete ionic equation turns out to be:

$2H^++2ClO^-+Sr^(2+)+2(OH)^-\rightarrow Sr^(2+)+2(ClO)^-+2H_2O(l)$

Whereas the spectator ions, which remain the same at both sides of the equation, are:

$ClO^-\n\nSr^(2+)$

Best regards!

Final answer:

A reaction occurs when HClO and Sr(OH)2 are mixed forming Sr(ClO)2 and H2O. In this reaction there are no spectator ions as all ions participate in the reaction forming new compounds.

Explanation:

When HClO (hypochlorous acid) and Sr(OH)2 (strontium hydroxide) solutions are mixed, a reaction takes place, resulting in the formation of Sr(ClO)2 and H2O. In this reaction, Sr2+ and OH- from Sr(OH)2 and H+ and ClO- from HClO are the ions that participate, therefore there are no spectator ions in the reaction. In the net ionic equation, spectator ions are the ions that remain the same in their ionic form on the both sides of the equation (reactant side and product side), thus, in this case, there are none. It's important to understand the concept of

solubility guidelines

and their use in determining reaction outcomes and recognizing

spectator ions

Learn more about Chemistry of Reaction here:

brainly.com/question/30344509

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You can measure length with the greatest precision using a tape measure marked in _____.A. meters
B. kilometers
C. millimeters
D. centimeters

Answers

Answer:

The answer is C

Explanation:

Precision generally means been accurate (and can be loosely interpreted to mean been exact). Length is averagely measured in meters. However, in order to get the actual length of a substance using a tape, millimeters give the most accurate length (of all the options) as it provides the length to the smallest details (of all the options provided). The illustration below shows the relationship between millimeters and the rest of the options.

while 1 kilometer = 1000 meters

1 meter = 100 centimeters

1 centimeter = 10 millimeters

From the relationship above, millimeters is clearly the most precise of all the options provided.

You can measure length wiht the greatest preciaion using a tape measure marked in milimeters.

Answer: C. milimeters.

There are two alloys, one is 1 part silver and 5 parts copper and the other 3 parts silver and 1 part copper are mixed to form 350 pounds of an alloy that is equal in silver and copper content.How many pounds of each should be used?

Answers

Lets make x equal the number times you use the 1/5 ratio alloy and y equal the number of times you use the 3/1 ratio alloy. You can make the equation (x+3y)-(5x+y)=0 and (x+3y)+(5x+y)=350
Then you can make the system of equation of:
-4x+2y=0 (this is y=2x)
6x+4y=350
You can make 6x+8x=350 by through substitution and solve of x.
14x=350
x=25 (which means y=50)

that means that the weight of the 1/5 ratio alloy is 150 pounds.
(25+(5x25))=150
the weight of the 3/1 ratio alloy is 200 pounds.
((50x3)+50)=200

I hope this helps.

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