An atom of elements x has one more shell of electrons than an atom of beryllium,but h are s one less valence electron then beryllium.which element is element X?

Answer:

162 g Fe₂O₃

Explanation:

To find the mass of Fe₂O₃, you need to (1) convert grams C to moles C (via molar mass from periodic table), then (2) convert moles C to moles Fe₂O₃ (via mole-to-mole ratio from reaction coefficients), and then (3) convert moles Fe₂O₃ to grams (via molar mass). It is important to arrange the ratios/conversions in a way that allows for the cancellation of units. The final answer should have 3 sig figs to reflect the given value.

Molar Mass (C): 12.011 g/mol

2 Fe₂O₃(s) + 3 C(s) ---> 4 Fe(s) + 3 CO₂(g)

Molar Mass (Fe₂O₃): 2(55.845 g/mol) + 3(15.998 g/mol)

Molar Mass (Fe₂O₃): 159.684 g/mol

18.3 g C           1 mole            2 moles Fe₂O₃          159.684 g
--------------  x  ----------------  x  -------------------------  x  -----------------  = 162 g Fe₂O₃
                        12.011 g              3 moles C                 1 mole

2Li + 2H2O____ 2LiaOH + 2H2

Answer:

2 Li + 2 H2O --> 2 LiaOH + 1 H2

Electrons in the Bohr model follow the number of elements in the rows of the periodic table.

2 in the first orbit

8 in the second and third ring

18 in the fourth etc...

The Bohr model is a simplistic means of explaining the placement of the subatomic particles of the elements of the periodic table.

The Bohr model arrangement of electrons follows the same pattern as the periodic table.

2 elements in the first row, and 2 electrons in the first orbit.

8 elements in the second row, and 8 electrons in the second orbit.

8 elements in the third row, and 8 electrons in the third orbit.

The fourth and fifth orbits would therefore hold 18 electrons.

For most chemists, the Bohr model does not work well beyond the third row of the periodic table because the model becomes quite oversized and bulky.

Based on the oxidation-reduction potential of the system, ratio of the concentration of the oxidized form to the concentration of the reduced form is 1 : 10.

The oxidation-reduction potential of a system is a measure of the tendency for a given chemical species to be reduced.

The reduction equation is as follows:

[tex]Fe^{3+} \rightarrow Fe^{2+} = 0.77\:V[/tex]

Using the equation:

[tex]E = E^{o} - \frac{0.0592}{n}log\frac{[Fe^{2+}]}{[Fe^{3+}]}[/tex]

n = 1; E⁰ = 0.77; E = 0.711

Substituting the values and using 1/x as the ratio:

[tex]0.711 = 0.77 - \frac{0.0592}{1} * log\frac{1}{x}[/tex]

x = 1/10

Therefore, the ratio of the concentration of the oxidized form to the concentration of the reduced form is 1 : 10.

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Answer:

0.004136 moles

Explanation:

From our question we have been asked to determine the quantity in moles of silver atoms having 2.49 × 10²¹ atoms of silver.

We know that from Avogadro's constant, one mole of silver contains 6.02 x 10²³ atoms.

Thus,

1 mole of silver contains 6.02 x 10²³ atoms.

x moles of silver contains 2.49 × 10²¹ atoms

Cross multiply to obtain the number of moles of silver,

x moles = (2.49 × 10²¹ x 1)/(6.02 x 10²³)

= 0.004136 moles

Therefore the quantity of silver in moles is 0.004136 moles

The conversion of heat to kinetic energy inside the water molecules causes the motion of the molecules to increase. The distance between molecules widens when the molecules move more quickly and clash more frequently. (As more heat is absorbed, the distance between molecules for solids, liquids, and gases widens)

Answer:

4.8 g H₂O

Explanation:

To find the mass of water, you need to (1) convert grams B₂H₆ to moles B₂H₆ (via molar mass from periodic table), then (2) convert moles B₂H₆ to moles H₂O (via mole-to-mole ratio from reaction coefficients), and then (3) convert moles H₂O to grams H₂O (via molar mass from periodic table).

It is important to arrange the ratios/conversions in a way that allows for the cancellation of units (the desired unit should be in the numerator). The final answer should have 2 sig figs because the given value (3.7 grams) has 2 sig figs.

Molar Mass (B₂H₆): 2(10.811 g/mol) + 6(1.008 g/mol)

Molar Mass (B₂H₆): 27.67 g/mol

1 B₂H₆ + 3 O₂ ---> 2 HBO₂ + 2 H₂O
^                                             ^

Molar Mass (H₂O): 15.998 g/mol + 2(1.008 g/mol)

Molar Mass (H₂O): 18.014 g/mol

3.7 g B₂H₆          1 mole            2 moles H₂O           18.014 g
----------------  x  ---------------  x  -----------------------  x  -----------------  =  4.8 g H₂O
                          27.67 g           1 mole B₂H₆              1 mole

Answer:

Place 20.0 g NaOH(s) in a flask and dilute to 1.00 L with water.

Explanation:

Answer:

The balanced chemical equation is P₄ (s) + 5O₂ (g) → P₄O₁₀ (s)

Explanation:

In order to balance the chemical equation, you first need to see what's out of balance.

In this case our Oxygen is not balanced, so in order to make the two the same, we need to see what coefficient we need to add to the compounds to balance the problem.

So, adding a coefficient of 5 to  the O₂ will result in an equal number of oxygen on both sides.

M = n/V

V = n/M

V = (14.5 : 56.1056)/2.8

V = 0.0923 L = 92.3 mL

Answer:

Explanation:Hyaluronic acid is a natural substance found in the fluids in the eyes and joints. It acts as a cushion and lubricant in the joints and other tissues.

Different forms of hyaluronic acid are used for cosmetic purposes. Hyaluronic acid might also affect the way the body responds to injury and help to decrease swelling.

Hyaluronic acid injections are US FDA-approved for several conditions, including cataracts, osteoarthritis, and as an injectable gel filler (Juvedérm) for facial wrinkles. People also commonly take hyaluronic acid by mouth and apply it to the skin for UTIs, acid reflux, dry eyes, wound healing, aging skin, and many other conditions, but there is no good scientific evidence to support most of these other uses.

How does it work ?

Uses & Effectiveness ?

Likely Effective for

Cataracts. Injecting hyaluronic acid into the eye is effective when used during cataract surgery by an eye surgeon.

Swelling (inflammation) and sores inside the mouth (oral mucositis). Applying an FDA-approved hyaluronic acid gel is effective for treating mouth sores. It's not clear if other products help.

Answer:

Explanation:

Hyaluronic acid is a natural substance found in the fluids in the eyes and joints. It acts as a cushion and lubricant in the joints and other tissues. Different forms of hyaluronic acid are used for cosmetic purposes. Hyaluronic acid might also affect the way the body responds to injury and help to decrease swelling.

(❛◡❛✿)!

Answer:

7.22 x 10¹⁰ ng Ni

Explanation:

To find the mass of nickel, you need to (1) convert moles to grams (via atomic mass from the periodic table) and then (2) convert grams to nanograms. These ratios need to be multiplied by each other, starting with the given value. It is important to arrange the conversions/ratios in a way that allows for the cancellation of units (the desired unit should be in the numerator). The final answer should have 3 sig figs to reflect the given value (1.23).

Atomic Mass (Ni): 58.693 g/mol

1 gram = 1 x 10⁹ nanograms

1.23 moles Ni             58.693 g               1 x 10⁹ ng
----------------------  x  ----------------------  x  ---------------------  =  7.22 x 10¹⁰ ng Ni
                                     1 mole                       1 g

V=n/M

V=(6.34:125.55 g/mol)/0.72

V=0.07 L = 70 ml

Answer:

55.5g of calcium chloride is produced in the reaction.

Explanation:

To calculate the amount of calcium chloride.

The reaction of calcium carbonate with hydrochloride acid gives calcium chloride

CaCO₃ +  2HCl  →  CaCl₂  + CO₂  +  H₂O

Mass of calcium carbonate (CaCO₃)= 50.0g

Molecular mass of CaCO₃ = Ca + C + O₃

                                             = 40+ 12 + 3(16) = 100g

No of moles of calcium carbonate CaCO₃ = given mass / molecular mass

                                                                          = 50g/ 100

                                                                            = 0.5 moles

Molecular mass of calcium chloride = 40+ 2(35.5)=(40+71.0)= 111g/mol

1 mole of calcium carbonate gives = 1 mole of calcium chloride

0.5 moles of calcium carbonate gives= 0.5 × 111g/mole

                                                                = 55.5g

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Answer:

Sulfur dioxide (SO2)

⇒ Why is this the best option?

To determine the polarity of the molecule, there are two requirements. The first one has a variety of terminal atoms, whereas the second has a lone pair on the center atoms. The molecule is polar if one of the requirements is met; else, it is nonpolar. The oxygen atom is a terminal atom because it surrounds the sulfur atom, which is the center element in the SO2 molecule's Lewis structure. In this molecule, there are two terminal oxygen atoms. If we look at the first criterion, we can see that it is not met because it calls for the presence of two separate terminal atoms.

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Answer:

299.83°K

Explanation:

So, kelvin is a means of measuring temperature, as the question implies. To convert Celsius, one form of measuring temperature, to Kelvin, another form of measuring temperature, we must know the conversion median. Our median is that 0°C = 273.15°K. So, now, as we know that 0°C = 273.15°K, 26.68°C = 273.15°K + 26.68°. Because 273.15K might as well be zero degrees celsius (according to our median 0°C = 273.15°K), we simply add 26.68° to 273.15K and get 299.83°K

1.66 M is the concentration of the chemist's working solution.

Molarity (M) is the amount of a substance in a certain volume of solution. Molarity is defined as the moles of a solute per litres of a solution. Molarity is also known as the molar concentration of a solution.

In this case, we have a solution of Zn(NO₃)₂.

The chemist wants to prepare a dilute solution of this reactant.

The stock solution of the nitrate has a concentration of 4.93 M, and he wants to prepare 620 mL of a more dilute concentration of the same solution. He adds 210 mL of the stock and completes it with water until it reaches 620 mL.

We want to know the concentration of this diluted solution.

As we are working with the same solution, we can assume that the moles of the stock solution will be conserved in the diluted solution so:

[tex]n_1[/tex]= [tex]n_2[/tex]  (1)

and we also know that:

n = M x [tex]V_2[/tex]

If we replace this expression in (1) we have:

[tex]M_1[/tex] x [tex]V_1[/tex]= [tex]M_2[/tex] x [tex]V_2[/tex]

Where 1, would be the stock solution and 2, the solution we want to prepare.

So, we already know the concentration and volume used of the stock solution and the desired volume of the diluted one, therefore, all we have to do is replace the given data in (2) and solve for the concentration which is [tex]M_2[/tex]:

4.93 x 210 =  620 x[tex]M_2[/tex]

[tex]M_2[/tex] = 1.66 M

This is the concentration of the solution prepared.

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Answer:

C.) lowering the pressure

Explanation:

As you can see, the liquid and gas phases are stacked right on top of each other. Since temperature is on the x-axis, this means that these phases exist at the same temperature (disregarding any other variables). This means that changing the temperature would not change the liquid phase to the gas phase.

If we want to get the sample into the gas phase, we need to manipulate the sample based on the y-axis. To lower the sample into the gas phase, we need to lower the pressure, which is the variable on the y-axis. This will work because pressure decreases as you go down the y-axis.

Answer:

36.3375 g

Explanation:

Answer:

1) mass and type of material

2) type of material

3) temperature

Explanation:

Answer:

For Ed

Explanation:

The first one is: The physical proprieties.

The second one is: The pH of the solution.

I've been seeing the same answers from above around though, so I may be wrong. But either way, I tried.

Answer:

c.

Explanation:

gravitational potential energy describes the amount of energy something could have based off of the amount of gravity acting on the object. so energy stored in height difference would be the best answer because gravity is acting on those objec6s

A complete ionic equation shows ions formed from each of the species. It also show the charge on each of the ions.It also shows all reactants as compounds or elements. The ions formed and their charges can only be inferred from this equation.

The net ionic equation shows  the chemical species involve in chemical reaction while the complete ionic equation also involve the spectator ions.

These ions are same in both side of chemical reaction and thus cancels out each other.

Their presence can not effect the equilibrium of reaction that's why these ions are omitted in net ionic equation.  

The net ionic equation state that whether precipitation is occur or not.

If the chemical reaction have no net ionic equation it means all are in aqueous from not precipitation occur.

Balanced Chemical equation:

HClO₂(aq) + NaOH(aq) → H₂O(l) + NaClO₂ (aq)

Ionic equation:

H⁺(aq) + ClO₂⁻(aq) + Na⁺(aq) + OH⁻(aq) → H₂O(l) + Na⁺(aq) + ClO₂⁻ (aq)

Net ionic equation:

H⁺(aq) + OH⁻(aq) → H₂O(l)  

The ClO₂⁻(aq) and Na⁺ (aq) are spectator ions that's why these are not written in net ionic equation.

The water can not be splitted into ions because it is present in liquid form.

Hence, The net ionic equation shows  the chemical species involve in chemical reaction while the complete ionic equation also involve the spectator ions.

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Answer:

Density = 0.0035 g/cm³

Explanation:

The density equation looks like this:

Density (g/cm³) = mass (g) / volume (cm³)

You have been given both the mass and volume. However, the given volume is not in the correct units. To convert cm to cm³, you should simply raise the given volume to the power of 3.

24 cm  =  (24 cm)³  =  24³cm³  =  13,834 cm³

Now, you can plug you mass and volume into the equation and solve for density. The final answer should have 2 sig figs to reflect the given values.

Density = mass / volume

Density = 48 g / 13,824 cm³

Density = 0.00347 g/cm³

Density = 0.0035 g/cm³

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Answer:

C

Explanation:

four chiral centers

Answer:

which is an example of analog device

Due to the reaction's slow process of producing ppt or a change in color.

Chemical reaction is defined as a procedure where one or more compounds, known as reactants, are changed into one or more new substances, known as products. Chemical reactions result in the formation of new chemical bonds between the atoms of the reactant molecules and the product particles' atoms. While there are the same number of atoms both before and after the chemical transition, there will be a change in the number of molecules.

When carbon dioxide and water combine, carbonic acid is created. The indicator changes color as a result of the water becoming slightly acidic due to carbon dioxide gas from exhaled breath. Dissolution causes a change in pressure. This suggests a physical alteration.

Thus, due to the reaction's slow process of producing ppt or a change in color.

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Synthetic materials are made from natural resources and can be used for many purposes.

Synthetic materials are made by chemically changing the starting substances to create a material with different characteristics. Some examples of synthetic materials are plastics, medicines, and new fuels.

A synthetic substance may be chemically identical to a naturally-occurring substance or may be different.

Item is made from a synthetic material :

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Answer:

It appears all of them are correct
Smaller drops will scatter around while maintaining their shape
Larger drop will spread stick to the surface.
and drops close together will join to form on gigantic sphere(but not perfect sphere)
and if they are in the sun, they'll eventually evaporate

Explanation:

When 1 mole of Zn and 2 mole of O₂ reacts togethor, It will produce 1 mole of ZnO as O₂ is excess reagent and Zn will act as Limiting reagent and thus it limits the amount of product formed.

Limiting reagents are the substances that are completely consumed first in a chemical reaction.

Given ;

Given equation ;

2Zn + O₂ --> 2ZnO

As according to given chemical equation,

2 moles Zn of reacts with 1 mole of O₂ to produce 2 moles of ZnO.

Therefore,

1 mole of Zn will require 0.5 mole of O₂.

But,

the given amount of O₂ is 2 mole which is excess

Hence,

Zn here will act as the Limiting reagent, According to which the amount of product formed will be decided.

Therefore,

If 2 mole Zn produces : 2 moles of ZnO (According to given balanced equation)

Thus,

1 mole of Zn will produce = 2/2 x 1

                                          = 1 mole of ZnO

Hence, When 1 mole of Zn and 2 mole of O₂ reacts togethor, It will produce 1 mole of ZnO as O₂ is excess reagent and Zn will act as Limiting reagent and thus it limits the amount of product formed.

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Answer:

17.5 Km

Explanation:

T = 3.5 hours

v = 5 K/hr

S = VT

S = 5 × 3.5

S = 17.5 Km