All categories

3 years ago

Uranium-238 decays into thorium-234.how do scientists explain why this happens

2 answers:

4 0

When an atom has more neutrons in the nucleus than protons, it is said to be unstable. The benchmark element for this is Iron. Iron is the most stable in nature. Logically, elements lighter than Iron undergo nuclear fusion (combining), while elements heavier than ion undergo nuclear fission (breaking). These elements spontaneously decay by giving off sub-atomic particles.

U-238 means that the Uranium isotope contains 238 neutrons and protons. We know that the atomic number of Uranium is equal to 92. Therefore, the number of neutrons is: 238 - 92 = 146 neutrons. So, U-238 contains 92 protons and 146 neutrons. Similarly, Thorium-234 having an atomic number of 90 will have an amount of neutrons equal to: 234 - 90 = 144 neutrons. Let's compare the difference between U-238 and Th-234:

Protons: 92 → 90
Neutrons: 146 → 144

Therefore, for U-238 to transform to Th-234, it must give off 2 protons and 2 neutrons. This is a characteristic of alpha decay or alpha radiation. It gives off an alpha particle during nuclear fission. An alpha particle is simply a Helium atom, which contains 2 protons and 2 neutrons.

natali 33 [55]3 years ago

3 0

Correct Answer:

The nucleus is unstable.

Thanks,

If this helped give me a thanks :D

You might be interested in

23.495 g sample of aqueous waste leaving a fertilizer manufacturer contains ammonia. The sample is diluted with 72.311 g of wate

Otrada [13]

Answer:

1.86% NH₃

Explanation:

The reaction that takes place is:

HCl(aq) + NH₃(aq) → NH₄Cl(aq)

We calculate the moles of HCl that reacted, using the volume used and the concentration:

32.27 mL ⇒ 32.27/1000 = 0.03227 L

0.1080 M * 0.03227 L = 3.4852x10⁻³ mol HCl

The moles of HCl are equal to the moles of NH₃, so now we calculate the mass of NH₃ that was titrated, using its molecular weight:

3.4852x10⁻³ mol NH₃ * 17 g/mol = 0.0592 g NH₃

The weight percent NH₃ in the aliquot (and thus in the diluted sample) is:

0.0592 / 12.949 * 100% = 0.4575%

Now we calculate the total mass of NH₃ in the diluted sample:

Diluted sample total mass = Aqueous waste Mass + Water mass = 23.495 + 72.311 = 95.806 g

0.4575% * 95.806 g = 0.4383 g NH₃

Finally we calculate the weight percent NH₃ in the original sample of aqueous waste:

0.4383 g NH₃ / 23.495 g * 100% = 1.86% NH₃

6 0

3 years ago

By increasing the length of heat exchanger, the effectiveness and cold stream output temperature of the heat exchanger

Dominik [7]

Answer:

Effectiveness and cold stream output temperature of the heat exchange Increases. So, Answer is b) Increases.

Explanation:

We have a heat exchanger, and it is required to compare the effectiveness and cold stream output if the length is increased.

Heat exchangers are engineering devices used to transfer energy. Thermal energy is transferred from Fluid 1 - Hot fluid (HF) to a Fluid 2 - Cold Fluid (CF). Both fluids 1 and 2 can flow with different values of mass flow rate and different specific heat. When the streams go inside the heat exchanger Temperature of Fluid 1 (HF) will decrease, at the same time Temperature of the Fluid 2 (CF) will increase.

In this case, we need to analyze the behavior taking into account different lengths of heat exchangers. If the length of the heat exchanger increases, it means the transfer area will increases. Heat transfer will increase if the transfer area increases. In this sense, the increasing length is the same than increase heat transfer.

If the heat transfer increases, it means Fluid 1 (HF) will reduce its temperature, and at the same time Fluid 2 (CF) will increase its temperature.

Finally, Answer is b) Effectiveness and cold stream output temperature increases when the length of the heat exchanger is increased.

5 0

3 years ago

Chlorophyll a is one of the green pigments found in plants. Chlorophyll a has the molecular formula C55H72MgN4O5. How many atoms

algol13

The number of atoms in a molecule can be calculated by adding all of the number of elements from the chemical formula. For chlorophyll, the chemical formula would be C55H72MgN4O5 adding all the elements we have 137 atoms. Hope this answers the question.

8 0

3 years ago

A gaseous mixture composed of 20% CH4, 30% C2H4, 35% C2H2, and 15% C2H20. What is the average molecular weight of the mixture? a

Semenov [28]

Answer: The correct answer is Option d.

Explanation:

We are given:

Mass percentage of $CH_4$ = 20 %

So, mole fraction of $CH_4$ = 0.2

Mass percentage of $C_2H_4$ = 30 %

So, mole fraction of $C_2H_4$ = 0.3

Mass percentage of $C_2H_2$ = 35 %

So, mole fraction of $C_2H_2$ = 0.35

Mass percentage of $C_2H_2O$ = 15 %

So, mole fraction of $C_2H_2O$ = 0.15

We know that:

Molar mass of $CH_4$ = 16 g/mol

Molar mass of $C_2H_4$ = 28 g/mol

Molar mass of $C_2H_2$ = 26 g/mol

Molar mass of $C_2H_2O$ = 48 g/mol

To calculate the average molecular mass of the mixture, we use the equation:

$\text{Average molecular weight of mixture}=\frac{_{i=1}^n\sum{\chi_im_i}}{n_i}$

where,

$\chi_i$ = mole fractions of i-th species

$m_i$ = molar masses of i-th species

$n_i$ = number of observations

Putting values in above equation:

$\text{Average molecular weight}=\frac{(\chi_{CH_4}\times M_{CH_4})+(\chi_{C_2H_4}\times M_{C_2H_4})+(\chi_{C_2H_2}\times M_{C_2H_2})+(\chi_{C_2H_2O}\times M_{C_2H_2O})}{4}$

$\text{Average molecular weight of mixture}=\frac{(0.20\times 16)+(0.30\times 28)+(0.35\times 26)+(0.15\times 42)}{4}\\\\\text{Average molecular weight of mixture}=6.75$

Hence, the correct answer is Option d.

3 0

3 years ago

I WILL MARK BRAINLIEST PLZ HELP ASAP, thanks :)

7nadin3 [17]

Answer:

Inner

Explanation:

3 0

3 years ago