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3 years ago

Describe the photoelectric effect and explain why it made modifications to the Rutherford model necessary.

2 answers:

7 0

Photoelectric effect refer to the emission of electron or free carriers when light shine into a material. According to the Rutherford model, light of any energy should be able to make electrons leave the atom and be emitted. The energy of the emitted electrons should be related to the intensity of the light. But the energy of the electron is actually only related to the energy of the light

Furkat [3]3 years ago

6 0

<span>Photoelectric effect refer to the emission of electron or free carriers when light shine into a material. According to the Rutherford model, light of any energy should be able to make electrons leave the atom and be emitted. The energy of the emitted electrons should be related to the intensity of the light. But the energy of the electron is actually only related to the energy of the light</span>

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A (12), B (8), C (4) out of these three elements, which two elements would show similar chemical properties?

fiasKO [112]

Answer: A and C

Explanation:

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3 years ago

What is formed when the number of electrons is changed?

aleksley [76]

Answer:

Explanation:

Whether the electrons are added or given away makes no difference to the name given to parent atom -- It is called an ion which means that it has a charge. The word atom is reserved for something on the periodic table that has no charge.

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3 years ago

A chemist requires 5.00 liters of 0.420 M H2SO4 solution. How many grams of H2SO4 should the chemist dissolve in water? 129 gram

natali 33 [55]

Answer:

Approximately 206 grams.

Explanation:

How many moles of sulfuric acid $\mathrm{H_2SO_4}$ are there in this solution?

$\text{Number of moles of solute} = \text{Concentration} \times \text{Volume}$ .

The unit for concentration " $\mathrm{M}$ " is equivalent to mole per liter. In other words, $\rm 1\;M = 1\; mol\cdot L^{-1}$ . For this solution, the concentration of $\mathrm{H_2SO_4}$ is $\rm 0.420\;M = 0.420\; mol\cdot L^{-1}$ .

$\begin{aligned}n(\mathrm{H_2SO_4}) &= c(\mathrm{H_2SO_4}) \cdot V\\&= \rm 0.420\;mol\cdot L^{-1}\times 5.00\; L \\&= \rm 2.10\; mol\end{aligned}$ .

What's the mass of that $\rm 2.10\; mol$ of $\mathrm{H_2SO_4}$ ?

Start by finding the molar mass $M$ of $\mathrm{H_2SO_4}$ .

Relative atomic mass data from a modern periodic table:

H: 1.008;
S: 32.06;
O: 15.999.

$\displaystyle M(\mathrm{H_2SO_4}) = 2\times \underbrace{1.008}_{\mathrm{H}} + 1\times \underbrace{32.06}_{\mathrm{S}} + 4\times \underbrace{15.999}_{\mathrm{O}} = \rm 98.072\;g\cdot mol^{-1}$ .

$\text{Mass} = \text{Quantity in moles} \times \text{Molar Mass}$ .

$m = n \cdot M = \rm 2.10\; mol \times 98.072\;g\cdot mol^{-1} \approx 206\; g$ .

In other words, the chemist shall need approximately 206 grams of $\mathrm{H_2SO_4}$ to make this solution. As a side note, keep in mind that the 206 grams of $\mathrm{H_2SO_4}$ also take up considerable amount of space. Therefore it will take less than 5.00 L of water to make the 5.00 L solution.

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4 years ago

I need help with this one pls, ty! ASAP

LuckyWell [14K]

Answer:

Explanation:

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When we say a motorcycle travels at the rate of 5m/s due east, we are describing the velocity of such body.

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Friction is a force that opposes motion. It prevents a body from moving.

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Weight is a measure of the amount of gravitational force on a body. It is mathematically expressed as;

W = mg

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3 years ago

Which of the follow statements about isotopes is NOT correct?

worty [1.4K]

Answer: B- Isotopes are often used for dating artifacts and fossils is incorrect.

Explanation: I hope that helped

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3 years ago