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3 years ago

What is a valence electron ?

2 answers:

6 0

a valence electron is an outer shell electron that is associated with an atom, and that can participate in the formation of a chemical bond if the outer shell is not closed; in a single covalent bond, both atoms in the bond contribute one valence electron in order to form a shared pair.

natulia [17]3 years ago

5 0

electron in the outermost energy ring

You might be interested in

Fe2O3 + 2Al = 2Fe + Al2O3 is this a redox reaction

katovenus [111]

Answer:

<h3>2Al+ Fe2O3 gives 2Fe + Al2O3. The given reaction is a redox reaction. As oxidation and reduction are taking place simultaneously.</h3>

Explanation:

like this...Identify oxidation and reduction with their agents:

<h3>•Fe2O3 is reduced to Fe whereas Al is oxidized to Al2O3</h3>

<h3>In the above reaction:</h3>

<h3>Oxidizing agent:Fe2O3</h3>

<h3>Reducing agent:Al</h3>

I hope it's help you (◠‿・)—☆

5 0

3 years ago

The equation below represents a double replacement/displacement reaction;

Naddik [55]

AB+XY->AY+XB
We know that the answer would be KCl because of the switching that takes place during a double displacement reaction. Just like Zn and MnO4 switched and combined, the remaining elements, K and Cl, will combine.
We know that the answer is simply KCl because both K and Cl have an ion of only +/-1, meaning when they cross, no suffixes are made, since their ions are only 1.
For example, if you combined Mg with Cl, you would get MgCl2, because Mg has an ion of +2.
I hope this helps!

4 0

3 years ago

HURRY PLEASE

katrin2010 [14]

Answers:

Question 1:

The diagram for gallium will have flat, horizontal lines at 30 and 2204 °C.

Questoin 2:

The diagram for methane will have a diagonal line representing the liquid phase between -183°C and -162°C.

Question 3:

For gold, the boiling point corresponds to the y-value at 2856 °C of the top horizontal line

Question 4.

For nitrogen, the line at -210°C will be flat, which represents the change from a solid to a liquid

Explanations:

Question 1:

The diagram for gallium will have flat, horizontal lines at 30 and 2204 °C.

The table shows that the melting point of gallium is 30°C and its boiling point is 2204°C.

Melting point is the temperature at which the substace changes its state from solid to liquid. During that change, the temperature of the substance does not change, because the heat supplied is used to accomplish the phase change. So, the temperature is constant and that means that portion of the diagram is flat.

The same is valid during boiling: the temperature remains constant while the substance is passing from liquid to gas at the boiling point.

Questoin 2:

The diagram for methane will have a diagonal line representing the liquid phase between -183°C and -162°C.

Between the melting (-183°C) and boiling (-162°C) points of methane, its temperature will increase more or less linearly, which is represented with a diagonal (slant) line between those points. During this interval the heat is used to increase the temperature and no phase of change happens.

Question 3:

For gold, the boiling point corresponds to the y-value at 2856 °C of the top horizontal line

The table shows that the boiling point of gold is 2,856°C.

In a temperature-vs.-time diagram the temperature is represented on the vertical axis (y-value) and the time is represented on the horizontal axis.

Since, the temperature of the substance does not change during boiling, the line during the time that this change of phase is happening is flat. And since this temperatue is higher than the melting temperature, this is the top horizontal line in the diagram.

Question 4.

For nitrogen, the line at -210°C will be flat, which represents the change from a solid to a liquid

The table shows that the melting point of nitrogen is -210°C, that means that the temperature will remain constant at -210°C while the substance is absorbing heat to pass from solid to liquid.

In conclusion, you must remember that all the phase changes, melting (from solid to liquid), freezing (from liquid to solid), boilng (from liquid to gas), and condensing (from gas to liquid) happens at constant temperature, and so the temperature - vs. - time diagrams show flat lines (constant y-values) during those intervals of time.

4 0

3 years ago

Read 2 more answers

Land breezes near bodies of water occur because

Aleksandr [31]

B) land cools off much faster than water (creating a air region of high density above land and lower density above sea)

6 0

4 years ago

The molar heat of fusion of gold is 12.550 kJ mol–1. At its melting point, how much mass of melted gold must solidify to release

KATRIN_1 [288]

The mass of melted gold to release the energy would be 3, 688. 8 Kg

<h3>How to determine the mass</h3>

The formula for quantity of energy is given thus;

Q = n × HF

Where n represents number of moles

HF represents heat of fusion

To find the number of moles, we have

235.0 = n × 12.550

number of moles = $\frac{235}{12. 550}$ = 18. 725 moles

Note that molar mass of Gold is 197g/ mol

Let's note that;

Number of moles = mass/ molar mass

Mass = number of moles × molar mass

Mass = 18. 725 × 197

Mass = 3, 688. 8 Kg

Thus, the mass of melted gold to release the energy would be 3, 688. 8 Kg

Learn more about molar heat of fusion here:

brainly.com/question/15634085

#SPJ1

8 0

2 years ago