help I have to do this before the end of the day!

Answer:

Two ions that produced similar colors in the flame test were Ca+2 and Sr+2. 3.

Explanation:

The colors are produced when an electron jumps to a higher level and then jump back down.

Ba2+ and Cu2+ and Sr2+ and Li+ were the pair with the similar color. Sr and Li displayed red colors, while Ba and Cu had mild greenish yellowish hues.

Why do some ions in the flame test generate colors that are similar?

The precise sizes of the potential energy jumps differ from metal to metal. As a result, the flame color of each metal will differ due to its unique spectral line pattern. The movement of the electrons in the metal ions contained in the compounds results in the hues of the flame.

The energy released by each electron when it returns to its initial condition determines the hue of the light that is produced.

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Answer:

29.854

Explanation:

12+17=29

.354+.5= 854

Therefore, to make 3.00 L of a 1.90 M solution of sodium hydroxide, 228 grammes of sodium hydroxide must be dissolved.

We need to dilute 40 grammes of sodium hydroxide in one litre of water in order to create a solution with a 1 molar concentration. You can make 1M NaOH solution by weighing 39.9 g of NaOH granules and dissolving them in 1 litre of water.

We can use the following method to calculate the mass of sodium hydroxide needed to make the solution:

m = M × V × MW

where:

m = mass of solute (in grams)

M = molarity of the solution (in moles per liter)

V = volume of the solution (in liters)

MW = molecular weight of the solute (in grams per mole)

Substituting the given values, we get:

m = 1.90 mol/L × 3.00 L × 40.00 g/mol

m = 228 g.

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Explanation:

please refer to the attached file (English)

s'il vous plaît se référer au fichier ci-joint cher compagnon (French)

The number of valance electron is 6

Valence electrons are the electrons found in the outermost shell of an atom.

The given atom has the following electronic configuration;

1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁴

The number of valence electron in a given electronic configuration is determine as follows;

The number of valance electron is found in this sub-orbitals = 4s², 4p⁴

The number of valance electron = 2 + 4 = 6

Thus, the number of valance electron is 6

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Answer:

Explanation:

limiting reactant is NaCl it is consumed completely)

calculate n for each product

  n NaCl (mole )                 n MgCl2(mole )

    2                                                1

    0.9                                              x

        x = 0.45 mole

 n NaCl                          n Na2O

  2                                      1

   0.900                    x

 x = 0.45 mole

  the total number of moles of reaction products is: 0.45 + 0.45= 0.9mol

Answer:

Absolute humidity

Explanation:

Answer:

the answer you are searching for is

Answer:

209

Explanation:

Answer:

Four half lives

Explanation:

Answer:

ammonium chloride

Explanation:

Because NH is ammonium and Cl is chlorine

]Answer:

[tex] H_2O + Mg [/tex]

Explanation:

A mixture is made up of two or more substances or constituents, which combine physically and can be easily separated. In a mixture, each constituent still maintains its identity and property in the combination.

Among the options given, the formula [tex] H_2O + Mg [/tex] represents a mixture of Water and Magnesium. This is a typical example of a substance that consists of 2 different substances that are combined physically.

Answer:

sodium(Na) is more active between Li and Na because is larger in size. Outermost electrons are less tightly held in sodium than in lithium. As a result, sodium loses its outermost electron more easily than lithium.

Answer:

Explanation:

14 protons

17 neutrons

18 electrons

Mass number = ?

Mass number = protons + neutrons.

[tex]Mass\:number = 14+17\\\\Mass \:number = 31[/tex]

Atomic number = ?

The number of protons = atomic number.

Atomic number = 14

Charge = ?

The charge of an element = number of protons minus the number of electrons.

[tex]Charge=14 -18\\\\Charge = -4[/tex]

Answer:

72.66%

Explanation:

NH₄Cl reacts in presence of NaOH producing ammonia, NH₃, as follows:

NH₄Cl + NaOH → NaCl + NH₃ + H₂O

The residual NaOH reacts with H₂SO₄ as follows:

2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O.

The equivalent-gram of H₂SO₄ are:

16mL * 0.1N * 1.06 = 1.696mEq.

As the complete residual solution is 100mL but the neutralization was made only with 10mL, the mEq you need to neutralize the residual NaOH is:

1.696mEq * (100mL / 10mL) = 16.96mEq.

The mEq of NaOH you add in the first are:

25mL * 0.95mEq = 23.75mEq

That means the NaOH that reacts = moles of NH₄Cl is:

23.75mEq - 16.96mEq = 6.79mEq = 6.79mmoles NH₄Cl =

6.79x10⁻³ moles NH₄Cl

In grams (Using molar mass NH₄Cl = 53.5g/mol):

6.79x10⁻³ moles NH₄Cl * (53.5g / mol) =

0.3633g of NH₄Cl are in the original mixture.

% is:

0.3633g/ 0.5g * 100 = 72.66%

The percentage of pure NH₄Cl in the mixture = 72.66%

Given data :

0.5 gm of mixture of NH₄Cl and NaCI

25 ml of 0.95 N NaOH

Determine the % of pure NH₄Cl in the mixture

Given that the reaction equation of the mixture is ;

NH₄Cl + NaOH ---->  NaCl + NH₃ + H₂O

And the residual solution reaction with H₂SO₄ is

2NaOH + H₂SO₄ ----> Na₂SO₄ + 2H₂O.

∴ H₂SO₄ ( equivalent gram )  = 16mL * 0.1N * 1.06 = 1.696

but the equivalent gram of H₂SO₄ required to neutralize NaOH = 1.696 * ( 100 mL / 10 mL ) = 16.96  

NaOH⁻ = 25mL * 0.95 = 23.75mEq ( from the first reaction equation )

next step : Determine the number of moles of NH₄Cl

 moles of NH₄Cl  = 23.75- 16.96 = 6.79 * 10⁻³

Final step : Calculate the % of pure NH₄CI in the mixture

moles of  NH₄Cl = 6.79 * 10⁻³

molar mass of  NH₄Cl  = 53.5g/mol

∴ mass of NH₄Cl = 6.79 * 10⁻³  * 53.5 = 0.3633g

% of pure NH₄CI in the mixture =  ( 0.3633 / 0.5 ) * 100 = 72.66%

Hence we can conclude that The percentage of pure NH₄Cl in the mixture is  72.66%

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Answer:

The correct answer is atomic mass

Explanation:

on engenuity

Answer:

The correct answer is atomic mass.

Explanation:

I took the quiz on edginuity

Given :

Two samples of matter differ in temperature by 20°C.

To Find :

The difference in temperature of these two samples using the  Kelvin scale.

Solution :

Let , initial and final temperature is [tex]T_i[/tex] and [tex]T_f[/tex] .

So , [tex]T_f-T_i=20^oC[/tex] .

Now , temperature in kelvin is given by [tex](T_i+273)[/tex] and [tex](T_f+273)[/tex] .

So , difference between them is :

[tex]=(T_f+273)-(T_i+273)\\\\=T_f-T_i\\\\=20\ K[/tex]

The difference in temperature of these two samples using the  Kelvin scale is 20 K .

Therefore , the magnitude of difference in kelvin and Celsius is same .

Hence , this is the required solution .

Answer:

1 cal = 0.004187 kJ

1,500,000 cal = 6280.5 kJ

Answer:

Being a reaction that releases heat, it is considered exothermic.

Explanation:

That is why if we consider it exothermic, the heat that is released to the medium is chemical energy lost from the interaction between the chemical bonds throughout the reaction. Having said this, we can affirm that the energy of the links of the products IS LESS than that of the REAGENTS, otherwise it happens in the endothermic ones, where it occurs in a vice versa.

These processes tend to have greater entropy and greater disorder in the reaction, greater kinetic energy between the particles.

Answer: Atoms that lose electrons acquire a positive charge as a result because they are left with fewer negatively charged electrons to balance the positive charges of the protons in the nucleus. Positively charged ions are called cations.

Atoms are made up of subatomic particles and gain or lose electrons to achieve the full electronic configuration and its octet.

The particle of matter has been constituted of at least a proton termed an atom. The electrons in orbitals and the protons and neutrons organized in a nucleus make up the main components of an atom.

Cations are the name given to ions that donate their electron. While anions are atoms that get extra electrons from other species. Seventeen protons and seventeen electrons make up a neutral chlorine atom. The octet needs one electron to be complete. Chlorine has the electrical configurations 2, 8, and 7, and will remain stable if it accepts an electron from a cation.

Therefore, atoms frequently absorb and lose electrons to maintain stability.

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Answer:

600K

Explanation:

PV=nRT

T=PV/nR

= 1.6atm* 15.0L/ 0.5mol*0.0821LatmK^-1mol^-1

=600K

Answer:

rocks beneath the surface melt seems like the answer that makes the most sense

Answer:

Rocks beneath the surface melt

Explanation:

Synthesis of reaction can be done by adding two or more reactants to form a product.

Equation for the water can be balanced as follow:

                             [tex]2H_{2} + O_{2} = 2H_{2}O[/tex]

The atoms of hydrogen are balanced on both the sides, also the oxygen are balanced.

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Answer:

Explanation:

The mass of a substance when given the density and volume can be found by using the formula

From the question

volume = 20 mL

density = 2 g/mL

The mass is

mass = 20 × 2

We have the final answer as

Hope this helps you

Answer:

The answer is

Explanation:

The mass of a substance when given the density and volume can be found by using the formula

From the question

volume of mercury = 15 mL

density = 13.55 g/cm³

The mass is

mass = 13.55 × 15

We have the final answer as

Hope this helps you

Answer:

Researchers at Virginia Tech decided to try using biochar to help reforest the post-mining site soil. They got permission to apply a layer of biochar to a post-mining site before it was reseeded and replanted.

Answer:

Explanation:

25.8 ml of .095 N NaOH is needed to neutralise the remaining acid

equivalent of NaOH used = 25.8 x .095 / 1000 = .002451 gm equivalent .

acid remaining = .002451 gm equivalent .

acid initially taken = 100 ml of .1 N  /  1000  = . 01 gm equivalent

acid reacted with metal = .01  -.002451 = .007549 gm equivalent

This must have reacted with same gram equivalent of metal oxide

.007549  gm equivalent = .15 gm of metal oxide

1 gm equivalent = 19.87 gm

equivalent weight of metal = 19.87 - equivalent weight of oxygen

= 19.87 - 8 = 11.87 .

1

Answer:

Fair Labor Standards Act

Explanation:

It is correct. I just took the test on Clever

Answer:

I would say it’s B

Explanation: