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3 years ago

Technetium-99m, a “metastable” nuclide of

1 answer:

4 0

In beta decay, a neutron is transformed into a proton via emission of an electron. This means that the total nucleon number remains the same; however, the proton number is increased by one (and the neutron number decreases by one). Therefore, the parent atom must also have mass number 99 but be of one less atomic number.
The atomic number of Tc is 43 and proton number 42 is Mo. Therefore, the answer is:
99Mo

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In thermodynamics, we determine the spontaneity of a reaction by the sign of ΔG. In electrochemistry, spontaneity is determined

faltersainse [42]

Answer:

For A: The standard cell potential of the reaction is 4.4 V

For B: The standard Gibbs free energy of the reaction is $-8.50\times 10^5J$

For C: The reaction is spontaneous as written.

Explanation:

For A:

The given chemical reaction follows:

$2Li(s)+Cl_2(g)\rightarrow 2Li^+(aq.)+2Cl^-(aq.)$

The given half reaction follows:

Oxidation half reaction: $Li(s)\rightarrow Li^+(aq.)+e^-;E^o_{Li^+/Li}=-3.04V$ ( × 2)

Reduction half reaction: $Cl_2(g)+2e^-\rightarrow 2Cl^-(aq.);E^o_{Cl_2/2Cl^-}=+1.36V$

The substance having highest positive $E^o$ potential will always get reduced and will undergo reduction reaction.

Here, chlorine will undergo reduction reaction will get reduced.

Substance getting oxidized always act as anode and the one getting reduced always act as cathode.

To calculate the $E^o_{cell}$ of the reaction, we use the equation:

$E^o_{cell}=E^o_{cathode}-E^o_{anode}$

$E^o_{cell}=1.36-(-3.04)=4.4V$

Hence, the standard cell potential of the reaction is 4.4 V

For B:

Relationship between standard Gibbs free energy and standard electrode potential follows:

$\Delta G^o=-nFE^o_{cell}$

where,

n = number of electrons transferred = $2mol\text{ e}^-$

F = Faradays constant = $96500J/V.mol\text{ e}^-$

$E^o_{cell}$ = standard cell potential = 4.4 V

Putting values in above equation, we get:

$\Delta G^o=-2\times 96500\times 4.4=-849200J=-8.50\times 10^5J$

Hence, the standard Gibbs free energy of the reaction is $-8.50\times 10^5J$

For C:

For a reaction to be spontaneous, the standard Gibbs free energy change of the reaction must be negative.

From above, the standard Gibbs free energy change of the reaction is coming out to be negative.

Hence, the reaction is spontaneous as written.

7 0

3 years ago

You have at your disposal 3 1-pound bags of various pure salts that dissolve readily in water. You can add one of the bags to a

Sedaia [141]

Answer:

This question appears incomplete

Explanation:

However, it should be noted that addition of soluble salts generally lowers the freezing point of water hence after the addition, water will no longer freeze at 0°C but lower.

Soluble salts tend to form more ions in water, it is these ions that are responsible for interfering with the hydrogen bonds hence lowering the freezing. Thus, (since each bag are of the same weight) the bag that contains the salt that ionizes more in water will lower the freezing point by the greatest amount.

NOTE: Different weight of the salts could lead to more ions been formed in the water by some salts as against the other.

6 0

4 years ago

List 3 elements that have similar properties or reactivity. Justify your answer with reasoning.

Rus_ich [418]

Answer:

Lithium, Potassium and Calcium

Explanation:

Because they are all in group one of the periodic table

7 0

3 years ago

Solve the following equation (y = 1.2345x – 0.6789) for x, given that y = 0.570

Andrews [41]

x = 1.01

Explanation:

Given equation:

y = 1.2345x – 0.6789

y = 0.570

Problem:

Solving for x

The variables in this equation are y and x

They can take up any value since they are variables.

Since we have been given y = 0.570

y = 1.2345x – 0.6789

To solve for x, we simply substitute for y in the equation;

since y = 0.570

0.57 = 1.2345x – 0.6789

add 0.6789 to both sides;

0.57 + 0.6789 = 1.2345x – 0.6789 + 0.6789

1.2489‬ = 1.2345x

Divide both sides by 1.2345

$\frac{1.2489}{ 1.2345} = \frac{ 1.2345x }{ 1.2345}$

x = 1.01

learn more:

Equations brainly.com/question/9045597

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7 0

3 years ago

A(n) _____ is equivalent to an electron. gamma ray omega particle alpha particle beta particle

ladessa [460]

Answer:

beta particle

Explanation:

Alpha beta and gamma radiations are the examples of ionizing radiations. When an atom is an excited state and having high energy, the atom is in unstable state. The excess of energy is released by the atom to get the stability. The released energy is in the form of radiations which may include alpha, beta, gamma, X-ray etc.

¹⁴₆C → ¹⁴₇N + ⁰₋₁e

The beta radiations are emitted in this reaction. The one electron is ejected and neutron is converted into proton.

Beta radiations:

Beta radiations are result from the beta decay in which electron is ejected. The neutron inside of the nucleus converted into the proton an thus emit the electron which is called β particle.

The mass of beta particle is smaller than the alpha particles.

They can travel in air in few meter distance.

These radiations can penetrate into the human skin.

The sheet of aluminium is used to block the beta radiations

3 0

3 years ago