How many valence electrons these elements have

Answer:

Answer:

"The elements are arranged in seven horizontal rows,called periods or series,and 18 vertical columns,called Groups."

Explanation:

Risk*

Answer:

Explanation:

i hope it helps :)

Answer:

Pathway

Explanation:

Pathways and Circuits are different things, so it can't be part of it.

Answer:

4NH₃ + 5O₂ —> 4NO + 6H₂O

Explanation:

NH₃ + O₂ —> NO + H₂O

The above equation can be balance as follow:

NH₃ + O₂ —> NO + H₂O

There 3 atoms of H on the left side and 2 atoms on the right side. It can be balance by 4 in front of NH₃ and 6 in front of H₂O as shown below:

4NH₃ + O₂ —> NO + 6H₂O

There are 4 atoms of N on the left side and 1 atom on the right side. It can be balance by putting 4 in front of NO as shown below:

4NH₃ + O₂ —> 4NO + 6H₂O

There are 2 atoms of O on the left side and a total of 10 atoms on the right side. It can be balance by putting 5 in front of O₂ as shown below:

4NH₃ + 5O₂ —> 4NO + 6H₂O

Thus, the equation is balanced.

Answer:

they have a fixed pair of magnets and a rolling coil they convert motion into electric energy they are powered by fosile fuels they use reletive motion of a magnet and coil of a wire

Explanation:

Answer:

They convert motion energy to electric energy.

They use the relative motion of a magnet and a coil of wire.

Explanation:

This is the correct answer.

Answer:

One possible answer could be lemon juice

Explanation:

We had to do a water test, and I was looking up what pH levels were. Then I learned about it in school, so I know a thing or two about it :)

Possible other answers include stomach acid and cola.

Hope this helps!!

Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 9.033×10²³ is the number of molecules in 1.500 mole of H[tex]_2[/tex]O.

The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number.

Mathematically,

number of atoms/molecules=number of moles × 6.022×10²³(Avogadro number)

number of moles =1.500 mole

substituting all the given values in the above equation, we get

number of atoms/molecules=1.500  × 6.022×10²³(Avogadro number)

number of atoms/molecules =9.033×10²³molecules

Therefore, 9.033×10²³ is the number of molecules in 1.500 mole of H[tex]_2[/tex]O.

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Answer:

Therefore, volume of CO₂ produced in the first step is 9141.404 L

Explanation:

Equations of reactions:

A: CaCO₃(s) ---> CaO(s) + CO₂(g)

B: CaO(l) + H₂O(l) ---> Ca(OH)₂(s)

Molar mass of CaCO₃ = 100 g; molar mass of CaO = 56 g; molar mass of CO₂ = 44 g molar mass of H₂P = 18 g; molar mass of Ca(OH)₂ = 74 g

From equation B, 1 mole of CaO produces 1 mole of Ca(OH)₂

This means that 56 g of CaO produces 74 g of Ca(OH)₂

mass of CaO that produces 8.47 kg or 8470 g of Ca(OH)₂ = 8470 g * 56/74 = 6409.73 g of CaO

Therefore, 6409.73 g of CaO were produced in reaction A

From reaction A, 1 mole of CaCO₃ produces 1 mole CaO and 1 mole of CO₂

Number of moles of CaO in 6409.73 g = 6409.73 g/56 g/mol = 114.46 moles

Therefore, 114.46 moles of CO₂ were produces as well.

Molar volume of gas at STP = 22.4 litres

Volume of CO₂ produced at STP = 114.46 * 22.4 L =2563.904 L

However, the above reaction took place at 950 K and 0.976 atm, therefore volume of CO₂ produced under these conditions are obtained using the general gas equation

Using P₁V₁/T₁ = P₂V₂/T₂

P₁ = 1.0 atm, V₁ = 2563.904 L, T₁ = 273 K, P₂ = 0.976 atm, T₂ = 950 K, V₂ = ?

V₂ = P₁V₁T₂/P₂T₁

V₂ = (1.0 * 2563.904 * 950)/(0.976 * 273)

V₂ = 9141.404 L

Therefore, volume of CO₂ produced in the first step is 9141.404 L

Number of particles inside a sugar bowl = 4.4 x 10²³

Given

The molar mass of sugar = 342.3 g/mol

mass of sugar = 250 g

Required

Number of particles

Solution

1 mol = 6.02 x 10²³ particles

mol of sugar :

[tex]\tt mol=\dfrac{mass}{molar~mass}[/tex]

mol = 250 g : 342.3 g/mol = 0.73 mol

Number of particles :

N = n x No

N = 0.73 x 6.02 x 10²³

N = 4.39 x 10²³ ≈ 4.4 x 10²³

Answer:

78.4g

Explanation:

Given parameters:

Mass of copper (II) chloride  = 90g

Mass of sodium nitrate  = 120g

Unknown:

Mass of sodium chloride that can be formed  = ?

Solution:

The balanced chemical reaction is:

            CuCl₂   +   2NaNO₃ →   Cu(NO₃)₂   +   2NaCl

Let us find the limiting reactant. This reactant will determine the extent of the reaction of the amount of product that will be formed.

First, convert the masses to number of moles;

      Number of moles  = [tex]\frac{mass}{molar mass}[/tex]

Molar mass of   CuCl₂  = 63.5 + 2(35.5) = 134.5g/mol

Molar mass of NaNO₃   = 23 + 14 + 3(16) = 85g/mol

  Number of moles of CuCl₂ = [tex]\frac{90}{134.5}[/tex]  = 0.67mole

  Number of moles of NaNO₃  = [tex]\frac{120}{85}[/tex]  = 1.41mole

From the balanced reaction equation:

      1 mole of CuCl₂   would react with 2 moles of NaNO₃

     0.67mole of CuCl₂   would require   0.67 x 2  = 1.34mole of NaNO₃

So, CuCl₂ is the limiting reactant

     1 mole of CuCl₂ will produce 2 mole of NaCl

    0.67mole of CuCl₂ will therefore yield 0.67 x 2 = 1.34mole of NaCl

Mass of NaCl = number of moles x molar mass

  Molar mass of NaCl = 23 + 35.5 = 58.5g/mol

Mass of NaCl  = 58.5 x 1.34  = 78.4g

Answer:

Energy produced deep inside Earth heats rock in the mantle. ... As it becomes less dense, the heated rock rises toward Earth's surface. The cooler, denser rock surrounding the heated rock sinks, as Figure 5 shows. In this way, heat inside Earth moves toward the cooler crust.

Explanation:

do you like my og name

Energy from Earth’s interior affect surface changes due to:

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Answer:

[tex]c=0.127\ J/g^{\circ} C[/tex]

Explanation:

Given that,

Mass of the sample, m = 275 g

It required 10.75 kJ of heat to change its temperature from 21.2 °C to its melting temperature, 327.5 °C.

We need to find the specific heat of the metal. The heat required by a metal sample is given by :

[tex]Q=mc\Delta T[/tex]

c is specific heat of the metal

[tex]c=\dfrac{Q}{m\Delta T}\\\\c=\dfrac{10.75\times 10^3\ J}{275\times (327.5 -21.2)}\\\\=0.127\ J/g^{\circ} C[/tex]

So, the specific heat of metal is [tex]0.127\ J/g^{\circ} C[/tex].

A longer wavelength means that it has a small frequency, so B.

In this case, red light has the longest wavelength on the spectrum. Anything past red will always have a smaller wavelength and it will always shrink until reaching violet.

Answer:

B

Explanation:

Higher frequencies have smaller wavelengths

Smaller frequencies have higher wavelengths

Answer:

group 15 ( the nitogen group)

Explanation:

Answer:

0.00047212

Explanation:

Given parameters:

Quantity of dumps  = 3.0099 dumps

Unknown:

Amount of wigs in this dumps = ?

Solution:

Since it is given that;

                 6375.23 dumps  = 1 wig

 To find 3.0099dumps;

                3.0099 dumps  =  x wigs

             6375.23x  = 3.0099

                           x  = [tex]\frac{3.0099}{6375.23}[/tex]   = 0.00047212 wig

Answer:

create a plan

the ways of of a student to set a goal

1. Write clear and measurable goals

2.Create a specific plan for each goal

3.Read your goals daily and visualize yourself accomplishing them

4. Reflect yourself to see if you are on target

5. Revise your action plans if needed.

1.)make a plan

2.)make a schedule

5.)pace him or herself

Answer:

Fe2O3,  Fe2S3 and FeCl3

Explanation:

The formular shows the number of atoms of element present in the compound. The number of atoms in turn depends on the charges. The goal is to have a neutral compound with oxidation number of zero.

Oxide:

Iron(Fe) has oxidation number (O.N) of +3, oxygen has O.N of -2. The formular with a balanced (Charge = 0) O.N number is; Fe2O3

Sulphide:

Iron(Fe) has oxidation number (O.N) of +3, sulphur has O.N of -2. The formular with a balanced (Charge = 0) O.N number is; Fe2S3

Chloride:

Iron(Fe) has oxidation number (O.N) of +3, chlorine has O.N of -1. The formular with a balanced (Charge = 0) O.N number is; FeCl3

Answer:

I am pretty sure it is C.

Explanation:

Because the wave frequency's tell us the number of waves there are on that diagram.

Answer:

C. the number of vibrations per second an object is making

Explanation:

Hope this helps. Sorry if it doesn't. T^T

Answer night

Explanation:

because day is to hot

The initial temperature of water in the beaker is 20⁰C .

Answer:

The answer is 9.000090040048176

Answer:

[tex]Mg(s)+2H^+(aq)\rightarrow Mg^{2+}(aq)+H_2(g)[/tex]

Explanation:

Hello!

In this case, since the writing of a net ionic equation first implies writing the complete molecular equation:

[tex]Mg(s)+2HCl(aq) \rightarrow MgCl_2(aq)+H_2(g)[/tex]

We can see that HCl and MgCl2 are ionized because they are aqueous, thus we write:

[tex]Mg(s)+2H^+(aq)+2Cl^-(aq) \rightarrow Mg^{2+}(aq)+2Cl^-(aq)+H_2(g)[/tex]

In such a way, we can cancel out the chloride ions as they are the spectator ones to obtain the net ionic one:

[tex]Mg(s)+2H^+(aq)\rightarrow Mg^{2+}(aq)+H_2(g)[/tex]

Best regards!

Answer:

it causes the cells to become flaccid and the stomata openings to close

Explanation:

the stomata closes to reduce water loss

When a plant is losing water at a greater rate than it can be replaced by its roots, then in such a case, the stomata will get close to reduce the loss of water.  

• Generally, the opening of stomata takes place in the day and gets close at night. To prevent the loss of water stomata get close during the night.  

• However, in certain cases, even during the day, when the plant experiences loss of water due to conditions like drought then stomata remain close during the day also.  

• This opening and closing of stomata take place as a response to the signals from the external environment.

Therefore, when more amount of water is loosing from the plant than getting absorbed by the roots, the stomata gets the signal to remain close to prevent water loss and death of the plant.

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Answer:

The partial pressure of helium gas in a gaseous mixture of helium and hydrogen is the pressure that the helium would exert in the absence of the hydrogen. equal to the total pressure divided by helium's molar mass. O equal to the total pressure divided by the number of helium atoms present.

Hope this Helps (✿◡‿◡)

Answer:

valence electrons

The elements in each group have the same number of electrons in the outer orbital. Those outer electrons are also called valence electrons. They are the electrons involved in chemical bonds with other elements. Every element in the first column (group one) has one electron in its outer shell.

Answer:

Theory- 1 to 7

Explanation:

Exercise- 8 to 25

ect

The right alternative is Option D (0.78 V).

According to the question,

By putting the values, we get

Cu+2 + 2e → Cu E = 0.52 V

Ag+1 + 1e Ag E° = 0.78 V

= 1.23 - 0.45

= 0.78.

negative

The standard cell potential is quite negative, so the reaction will not occur spontaneously as written.

Missing parts of the question.

Using the two cell reduction potentials shown for their corresponding reaction, calculate the cell potential for a voltaic cell made from these two systems: 0.78.

Cu+2 + 2e → Cu E = 0.52 V

Ag+1 + 1e Ag E° = 0.80 V

options:

A)

0.28 V

B)

–1.32 V

C)

1.32 V

D)

–0.28 V

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