What law allows calories to be determined by heat (energy) transfer from one substance to another, but it is never destroyed?

tamaranim1 [39]

Protons is the answer

5 0

2 years ago

The product of the nuclear reaction in which 40Ar is subjected to neutron capture followed by alpha emission is ________. The pr

Orlov [11]

Answer:

37S

Explanation:

Radioactivity is the spontaneous emission of particles and / or electromagnetic radiation by unstable atomic nuclei leading to their disintegration.

We have two main types of radioactivity: radioactive decay and artificial transmutation.

In radioactive decay ( natural radioactivity ), a naturally occurring radioactive element like Uranium-238 disintegrates or decays into more stable isotopes with the emission of particles and/or radiation.

23892U = 23490Th + 42He

Artificial transmutation is the collision of two particles where one particle captures the other used to bombard it. There is subsequent production of isotopes similar or different from the bombarded particle. Neutrons, alpha particles ( helium nucleus ), electrons, protons can be used to bombard elements.

147N + 42He = 178O + 11P

For the above question which is artificial transmutation, the reaction equation is

4018Ar + 10n = 3716S + 42He

So, the neutron capture by Argon-40 will produce a radioisotope Sulphur-37 with the emission of an alpha particle.

5 0

2 years ago

In this prelab exercise, you will calculate how to prepare solutions that you will make in lab. Below is an example of how to pr

Anastasy [175]

Explanation:

$Molarity=\frac{\text{Moles of compound}}{\text{Volume of solution (L)}}$

Moles of compound =

$\frac{\text{mass of compound}}{\text{Molar mass of compound}}$

We have ;

Volume of solution = 600 mL = 0.600 L ( 1 mL = 0.001 L)

Moles of NaOH = n

Molarity of the solution = 3 M

$3M=\frac{n}{0.600 L}$

n = 3 M × 0.600 L = 1.800 mol

Mass of 1.800 mole sof NaOH :

1.800 mol × 40 g/mol = 72.0 g

Preparation:

Weight 72.0 grams of sodium hydroxide and add it to the 500 mL of volumetric flask along with some water. Dissolve the all the solute by adding small proportion of water. After the solution becomes clear make the water upto the mark of 500 ml.

Transfer the solution to a bigger beaker and 100 mL of water more to it.

6 0

2 years ago

The two naturally occurring isotopes of antimony, 121Sb (57.21 percent) and 123Sb (42.79 percent), have masses of 120.904 and 12

Alex

Answer:

The correct answer is option c.

Explanation:

Formula used to determine an average atomic mass :

$\text{Average atomic mass }=\sum_{i=1}^n\text{(Atomic mass of an isotopes)}_i\times \text{(Fractional abundance})_i$

Mass of isotope Sb-121 = 120.904 amu

Fractional abundance of Sb-121 = 57.21% = 0.5721

Mass of isotope Sb-123 = 122.904 amu

Fractional abundance of Sb-123 = 42.79% = 0.4279

Average atomic mass of Sb:

$120.904 amu\times 0.5721+ 122.904 amu\times 0.4279=121.7598 amu \approx 121.76 amu$

7 0

2 years ago

Calculate the bond energy per mole for breaking all the bonds in methane, CH4. Express your answer to four significant figures a

lesantik [10]

The energy that is essential to break one C-H bond is 414 kJ/mol. Since, there are four C-H bonds in CH4, the energy Δ HCH4 for breaking all the bonds is calculated as Δ HCH4 = 4 x bond energy of C-H bond. By multiplying the 4 with the 414 kJ/mol you can get the answer of 1656 kJ/mol CH4 molecules.

4 0

2 years ago

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