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3 years ago

What is radio isotopes?

2 answers:

7 0

Radioactive isotope, also called radioisotope, radionuclide, or radioactive nuclide, any of several species of the same chemical element with different masses whose nuclei are unstable and dissipate excess energy by spontaneously emitting radiation in the form of alpha, beta, and gamma rays.

Julli [10]3 years ago

4 0

Any of the same chemical element with different masses whose nuclei are unstable and gets energy by emitting radiation in the form of alpha, beta, and gamma rays.

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Please help someone asap

stiv31 [10]

Answer:

transitive verb. 1 : to prove wrong by argument or evidence : show to be false or erroneous. 2 : to deny the truth or accuracy of refuted the allegations.

Explanation:

8 0

2 years ago

Read 2 more answers

Which layer over time due to chemical and physical weathering leads to the other layers?

ivanzaharov [21]

Answer:

chemical weathering occurs on the surface of minerals, the water and acids that control chemical weathering require access to the surface. Physical weathering breaks the rock to provide that surface

7 0

2 years ago

How much of a 0.74mg sample of uranium-235 will remain after 2.8x10^9

ankoles [38]

Of Uranium-235 remains after 2.8 x 10^9 years, what was the original mass of the sample of Uranium-235? The half-life of Uranium-235 is 7.0 x 10^8 years. Uranium-232 has a half life of 68.8 years.

5 0

2 years ago

Calculate the standard enthalpy of formation of liquid methanol, CH3OH(l), using the following information: C(graphite) + O2 --&

Darya [45]

Answer : The standard enthalpy of formation of methanol is, -238.7 kJ/mole

Explanation :

Standard formation of reaction : It is a chemical reaction that forms one mole of a substance from its constituent elements in their standard states.

According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.

According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.

The formation reaction of $CH_3OH$ will be,

$C(s)+2H_2(g)+\frac{1}{2}O_2\rightarrow CH_3OH(g)$ $\Delta H_{formation}=?$

The intermediate balanced chemical reaction will be,

(1) $C(graphite)+O_2(g)\rightarrow CO_2(g)$ $\Delta H_2=-393.5kJ/mole$

(2) $H_2(g)+\frac{1}{2}O_2(g)\rightarrow H_2O(l)$ $\Delta H_3=-285.8kJ/mole$

(3) $CH_3OH(g)+\frac{3}{2}O_2(g)\rightarrow CO_2(g)+2H_2O(l)$ $\Delta H_1=-726.4kJ/mole$

Now we will reverse the reaction 3, multiply reaction 2 by 2 then adding all the equations, we get :

(1) $C(graphite)+O_2(g)\rightarrow CO_2(g)$ $\Delta H_1=-393.5kJ/mole$

(2) $2H_2(g)+2O_2(g)\rightarrow 2H_2O(l)$ $\Delta H_2=2\times (-285.8kJ/mole)=-571.6kJ/mol$

(3) $CO_2(g)+2H_2O(l)\rightarrow CH_3OH(g)+\frac{3}{2}O_2(g)$ $\Delta H_3=726.4kJ/mole$

The expression for enthalpy of formation of $C_2H_4$ will be,

$\Delta H_{formation}=\Delta H_1+\Delta H_2+\Delta H_3$

$\Delta H=(-393.5kJ/mole)+(-571.6kJ/mole)+(726.4kJ/mole)$

$\Delta H=-238.7kJ/mole$

Therefore, the standard enthalpy of formation of methanol is, -238.7 kJ/mole

6 0

3 years ago

Can someone help me 4.how does gravity influence the motion of planets?

qaws [65]

Gravity is a very important force. Every object in space exerts a gravitational pull on every other, and so gravity influences the paths taken by everything traveling through space. It is the glue that holds together entire galaxies. It keeps planets in orbit.

Hope this helps.

5 0

3 years ago