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3 years ago

The speed of light in four different materials is shown below:

Chemistry

1 answer:

11Alexandr11 [23.1K]3 years ago

7 0

Material C. the less dense is easier to move through than the more dense, so the light moves faster. Its like light moving through less dense glass, then moving through a more dense wall.

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How are compound, elements, and mixure different

Fofino [41]

Explanation:

Compound: a substance that is made up of more than 1 type of atom bonded together Example: H2O

Mixture: combination of two or more elements or compounds not chemicaly bonded together. example: Sugar and salt in one container

elements pure substance of an atom. Example: hydrogen

6 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

PLS HELP ASAP i really need an answer a correct one

nata0808 [166]

Answer: 67.23 L

Explanation:

According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number $6.023\times 10^{23}$ of particles.

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Putting in the values we get:

$\text{Number of moles of methane}=\frac{48g}{16g/mol}=3moles$

1 mole of methane occupies = 22.4 L

Thus 3 moles of methane occupy = $\frac{22.4}{1}\times 3=67.23L$

Thus volume of 48 grams of methane gas is 67.23 L

6 0

3 years ago

Select the statements that correctly describe an asteroid. Check all that apply

stich3 [128]

Answer:

Explanation:

Most of this ancient space rubble can be found orbiting the Sun between Mars and Jupiter within the main asteroid belt. Asteroids range in size from Vesta – the largest at about 329 miles (530 kilometers) in diameter – to bodies that are less than 33 feet (10 meters) across.

5 0

3 years ago

If the energy of the reactants is less than

expeople1 [14]

The opposite type of reaction (where energy is taken in from the surroundings of a reaction and thus the energy of the reactants is lower than that of the products) is called an endothermic reaction

7 0

3 years ago