Calculate the solubility of Hg2Cl2 given that its ksp is 1.1*10^-18?

15. If the moon is 384,400km away. Does it take more than a second for light to travel from the Earth to the moon?

marishachu [46]

Answer:

Yes

Explanation:

The speed of light is about 300 000 km per second, so light takes about 1.28 seconds to travel from the Moon to the Earth.

3 0

1 year ago

The Tris/Borate/EDTA buffer (TBE) is commonly made as a 5x solution. What volumes of 5x TBE and water are required to make 500 m

Alexeev081 [22]

Answer:

50 ml (5x TBE) + 540 ml (water)

Explanation:

To prepare 0.5x TBE solution from 5x TBE solution we need to use the following dilution formula:

C1 x V1 = C2 x V2, where:

- C1, V1 = Concentration/amount (start), and Volume (start)

- C2, V2 = Concentration/amount (final), and Volume (final)

* So when we applied this formula it will be:

5 x V1 = 0.5 x 500

V1= 50ml

- To prepare 0.5x we will take 50ml from 5x and completed with 450ml water and the final volume will going to be 500ml.

8 0

4 years ago

How much energy is released by the decay of 3 grams of 230Th in the following reaction 230 Th - 226Ra + "He (230 Th = 229.9837 g

Serhud [2]

<u>Answer:</u> The energy released for the decay of 3 grams of 230-Thorium is $2.728\times 10^{-15}J$

<u>Explanation:</u>

First we have to calculate the mass defect $(\Delta m)$ .

The equation for the alpha decay of thorium nucleus follows:

$_{90}^{230}\textrm{Th}\rightarrow _{88}^{226}\textrm{Ra}+_2^{4}\textrm{He}$

To calculate the mass defect, we use the equation:

Mass defect = Sum of mass of product - Sum of mass of reactant

$\Delta m=(m_{Ra}+m_{He})-(m_{Th})$

$\Delta m=(225.9771+4.008)-(229.9837)=1.4\times 10^{-3}amu=2.324\times 10^{-30}kg$

(Conversion factor: $1amu=1.66\times 10^{-27}kg$ )

To calculate the energy released, we use Einstein equation, which is:

$E=\Delta mc^2$

$E=(2.324\times 10^{-30}kg)\times (3\times 10^8m/s)^2$

$E=2.0916\times 10^{-13}J$

The energy released for 230 grams of decay of thorium is $2.0916\times 10^{-13}J$

We need to calculate the energy released for the decay of 3 grams of thorium. By applying unitary method, we get:

As, 230 grams of Th release energy of = $2.0916\times 10^{-13}J$

Then, 3 grams of Th will release energy of = $\frac{2.0916\times 10^{-13}}{230}\times 3=2.728\times 10^{-15}J$

Hence, the energy released for the decay of 3 grams of 230-Thorium is $2.728\times 10^{-15}J$

5 0

3 years ago

Naturally occurring neon exists as three isotopes. 90.51% is ne-20 with a mass of 19.99 amu, 0.27% is ne-21 with a mass of 20.99

gregori [183]

The atomic mass of an element is the average relative mass of its atoms as compared with an atom of carbon-12 whose mass is taken as 12. In terms of percentages of different isotopes, the average atomic mass can be determined as follows: $A_{average}$ = ∑( $p_{i}$ X $A_{i}$ )/100. Where, $p_{i}$ is the percentage abundance of isotope with atomic number $A_{i}$ .