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3 years ago

Which pair of elements can be used to determine the age of a fossil that is over one billion years old?

Chemistry

3 answers:

AnnZ [28]3 years ago

7 0

Answer: Option (4)

Explanation: The most efficient radioactive method used for the determination of fossil age which is about one billion years old is the Potassium-Argon method (⁴⁰K-⁴⁰Ar).

Potassium-Argon method is generally used to date fossils which are more than 1.2 billion years old as its half life is almost about 1.2 billion years. Potassium is highly radioactive, which converts into Argon and becomes stable.

Uranium and Carbon are also highly radioactive whereas Lead and Nitrogen are stable elements.

¹⁴C-¹⁴N is not an efficient method as it has a half life of only about 5700 years.

Thus the correct answer is option (4).

lakkis [162]3 years ago

3 0

Answer:

Explanation:

There are some radioactive nuclides can be used to measure time on an archeological scale. One is the best example of this is radiocarbon dating. This process is based on the ratio of caebon-14 to carbon-12 in the atmosphere which is relatively constant.

The half time of C-14 5730 years

Carbon-14 is a radioactive nucleus. It has a half-life of 5730 years.

All living tissues like plants and animal absorbed carbon-12 along with carbon-14 with same ratio of caebon-14 to carbon-12 in the atmosphere.

Carbon-14 dating is based on the ratio of carbon-14 to carbon-12 in the atmosphere which is relatively constant

Cat 1012 years ago

0 0

It is D, or the last one, or potassium, which is radioactive, and argon, which is stable. lol!

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2. A sample of gas has a pressure of 195 kPa and a volume of 3.50 L. If the pressure

zhannawk [14.2K]

Answer:

Explanation:

The new volume can be found by using the formula for Boyle's law which is

$P_1V_1 = P_2V_2$

Since we're finding the new volume

$V_2 = \frac{P_1V_1}{P_2} \\$

We have

$V_2 = \frac{195000 \times 3.5}{150000} = \frac{682500}{150000} \\ = 4.55$

We have the final answer as

Hope this helps you

7 0

3 years ago

A fixed amount of gas in a rigid container is heated from 300 k to 900 k, which of the following responses best describes what w

Llana [10]

Answer: Option d. pressure increase by a factor of 3

Explanation:

P1 = P

T1 = 300k

T2 = 900K

P2 =?

Volume is constant.

P1/T1 = P2/T2

P/300 = P2/900

P2 x 300 = P x 900

P2 = (P x 900)/300

P2 = 3P

The pressure increased by a factor of 3

4 0

3 years ago

Specify which indicator or indicators you would use for the following titrations:

Helen [10]

Answer:

1. Phenolphthalein

2. Phenolphthalein

3. Methyl orange

Explanation:

Different indicators are used by knowing the relative strength of the acid and the bases I.e whether the acid is strong or weak, so also the base.

The following answers are obtainable:

1. Phenolphthalein

We use this indicator for a weak base and a strong acid. Formic acid is a weak organic acid while sodium hydroxide is a strong base

2. Phenolphthalein

We use this indicator because we are dealing with a strong acid and a strong base. Hydrochloric acid is a strong acid while potassium hydroxide is a strong base

3. Methyl orange

This is because we are dealing with a strong acid and a weak base

5 0

3 years ago

This is the answer fellas

lubasha [3.4K]

Answer:

Thx man!

Explanation:

Brainliest Please!

5 0

3 years ago

The equilibrium constant for the reaction 2NO(g)+Br2(g)⥫⥬==2NOBr(g) is Kc=1.3×10−2 at 1000 K. At this temperature does the equil

o-na [289]

Answer :

The equilibrium favors NO and $Br_2$ .

(1) The value of equilibrium constant for this reaction is, 76.9

(2) The value of equilibrium constant for this reaction is, 8.77

Explanation:

The given chemical equation is:

$2NO(g)+Br_2(g)\rightarrow 2NOBr(g)$

The value of equilibrium constant for the above equation is $K_c=1.3\times 10^{-2}$ .

The value of $K_c$ that means equilibrium lies to the left side. Thus, the equilibrium favors NO and $Br_2$ .

We need to calculate the equilibrium constant for the given equation of above chemical equation, which is:

(1) $2NOBr(g)\rightarrow 2NO(g)+Br_2(g)$

The equilibrium constant for the reverse reaction will be the reciprocal of the initial reaction.

The value of equilibrium constant for reverse reaction is:

$K_{c_1}=\frac{1}{K_c}$

$K_{c_1}=\frac{1}{1.3\times 10^{-2}}=76.9$

Thus, the value of equilibrium constant for this reaction is, 76.9

(2) $NOBr(g)\rightarrow NO(g)+\frac{1}{2}Br_2(g)$

The equilibrium constant for the reverse reaction will be the reciprocal of the initial reaction.

If the equation is multiplied by a factor of '1/2', the equilibrium constant of the reverse reaction will be the 1/2 power of the equilibrium constant of initial reaction.

The value of equilibrium constant for reverse reaction is:

$K_{c_2}=(\frac{1}{K_c})^{1/2}$

$K_{c_2}=(\frac{1}{1.3\times 10^{-2}})^{1/2}=8.77$

Thus, the value of equilibrium constant for this reaction is, 8.77

7 0

3 years ago

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