Help science!! *10 points*

How many Valance electrons are in an atom of phosphorous

densk [106]

Answer:

Five

Explanation:

Valance electrons are the outermost electrons in an atom. There are five electrons in the third layer of the phosphorus atom. So your answer is five valance electrons.

7 0

2 years ago

This question involves two calculations. The answer to the first part will be

ozzi

Answer :

(a) The mass of $Al_2O_3$ produced is, 15.2 grams.

(b) The percent yield of the reaction is, 72.5 %

Explanation :

Part (a) :

Given,

Mass of $Al$ = 85.1 g

Molar mass of $Al$ = 27 g/mol

First we have to calculate the moles of $Al$

$\text{Moles of }Al=\frac{\text{Given mass }Al}{\text{Molar mass }Al}=\frac{85.1g}{27g/mol}=3.15mol$

Now we have to calculate the moles of $Al_2O_3$

The balanced chemical equation is:

$4Al+3O_2\rightarrow 2Al_2O_3$

From the reaction, we conclude that

As, 4 moles of $Al$ react to give 2 moles of $Al_2O_3$

So, 3.15 moles of $Al$ react to give $\frac{2}{4}\times 3.15=1.58$ mole of $Al_2O_3$

Now we have to calculate the mass of $Al_2O_3$

$\text{ Mass of }Al_2O_3=\text{ Moles of }Al_2O_3\times \text{ Molar mass of }Al_2O_3$

Molar mass of $Al_2O_3$ = 102 g/mole

$\text{ Mass of }Al_2O_3=(1.58moles)\times (102g/mole)=161.2g$

Therefore, the mass of $Al_2O_3$ produced is, 161.2 grams.

Part (b) :

Now we have to calculate the percent yield of the reaction.

$\text{Percent yield}=\frac{\text{Experimental yield}}{\text{Theoretical yield}}\times 100$

Experimental yield = 116.9 g

Theoretical yield = 161.2 g

Now put all the given values in this formula, we get:

$\text{Percent yield}=\frac{116.9g}{161.2g}\times 100=72.5\%$

Therefore, the percent yield of the reaction is, 72.5 %

8 0

2 years ago

Explain how a nuclear power plant functions and what safety precautions must be taken to ensure the safety of the power plant, i

Talja [164]

Nuclear energy originates from the splitting of uranium atoms – a process called fission. This generates heat to produce steam, which is used by a turbine generator to generate electricity. Although renewable energy sources, like wind and solar power, are important resources for a country’s energy mix, only nuclear power is capable of producing large amounts of electricity 24 hours a day, 365 days a year.

For safety precaution which regards to employees, several federal agencies—the US Nuclear Regulatory Commission (NRC), the U.S. Environmental Protection Agency and the U.S. departments of Energy and Transportation—establish radiation protection regulations for U.S. nuclear plants based on internationally recognized scientific studies.

For the safety precaution of power plants itself, The NRC monitors plant performance according to three strategic areas: reactor safety, radiation safety and security.

7 0

2 years ago

Read 2 more answers

What is the percent ionization of a monoprotic weak acid solution that is 0.188 M? The acid-dissociation (or ionization) constan

djyliett [7]

Answer: The percent ionization of a monoprotic weak acid solution that is 0.188 M is $3.59\times 10^{-4}\%$