The period that an element is in on the periodic table can tell you how many _____ the element’s atom have.

A. Energy level(electron shells)
B. valence electrons
C. protons
D. isotopes
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PLUS 15 Points

Answer:

20.180042 amu

Explanation:

From the question given above, the following data were obtained:

Isotope A (20Ne)

Mass of A = 19.9924356 amu

Abundance (A%) = 90.48%

Isotope B (21Ne):

Mass of B = 20.9938428 amu

Abundance (B%) = 0.27%

Isotope C (22Ne):

Mass of C = 21.9913831 amu

Abundance (C%) = 9.25%

Average atomic mass of Neon =.?

The average atomic mass of Neon can be obtained as follow:

Average atomic mass = [(mass of A × A%)/100] + [(mass of B × B%)/100] + [(mass of C × C%)/100]

= [(19.9924356 × 90.48)/100] + [(20.9938428 × 0.27) /100] + [(21.9913831 × 9.25) /100]

= 18.0891557 + 0.05668338 + 2.03420294

= 20.180042 amu

Therefore, the average atomic mass of Neon is 20.180042 amu

Answer:

V = 43.95 L

Explanation:

Given data:

Mass of CH₄ decomposed = 15.63 g

Volume of H₂O produced at STP = ?

Solution:

Chemical equation:

CH₄ + 2O₂    →       2H₂O  + CO₂

Number of moles of CH₄:

Number of moles = mass/molar mass

Number of moles = 15.63 g/ 16 g/mol

Number of moles = 0.98 mol

Now we will compare the moles of H₂O with CH₄.

                         CH₄              :              H₂O

                           1                 :                2

                        0.98             :            2×0.98 = 1.96 mol

Volume of hydrogen:

PV = nRT

1 atm × V = 1.96 mol × 0.0821 atm.L/mol.K × 273.15 K

V = 43.95atm.L / 1atm

V = 43.95 L

Answer:

forensic scientist

Explanation:

forensic science is the discipline in which professionals use scientific means to analyze physical crime evidence. this evidence is then presented in court in order to help determine the innocence or guilt of a specific suspect.

Answer:

Its a forensic scientist :D

Explanation:

I took a test and got it wrong but it showed the right answer and its a forensic scientist

(don't ask how i got it wrong i was rushing!!)

Answer:

68.48%

Explanation:

The percent mass of an element in a compound tells us about the amount of such element contributed to the total compound.

In this case, 7.28 g sample of chromium metal was heated to produce chromium oxide with weight of 10.63 g. The percent mass of chromium in chromium oxide can be calculated by using the formula:

%mass of Cr = mass of Cr/mass of Chromium oxide × 100%

%mass of Cr = 7.28/10.63 × 100

%mass of Cr = 0.6848 × 100

%mass of Cr = 68.48%

Answer:

Zero

Explanation:

An an equal mixture of the R and S enantiomers of carvone is called a racemic mixture.

In a racemic mixture, the R enantiomer rotates plane polarized light in one direction while the S enantiomer rotates plane polarized light in another direction.

This cancels out the rotation due to each enantiomer since they are equal in magnitude but opposite in direction leading to a specific rotation of zero for the racemic mixture.

Answer:

hbyiy

Explanation:

Answer:

B) . six electrons in the triple bond of diatomic nitrogen

Explanation:

The three line in this Lewis dot structure represents the six electrons in the triple bond of diatomic nitrogen.

Nitrogen is made up of 7 electrons with 5 valence ones.

 A lewis structure is made up of the symbol of the element surrounded by dot to represent the valence electrons.

  In this nitrogen molecule, both species share  6 electrons. This makes each nitrogen atom isoelectronic with neon.

Answer:

one example of chemical weathering is when carbon dioxide mixes with water.

Explanation:

when dioxide mixes with water it creates carbonation.

Answer:

for electricity, watts as in back to the future "1.21 jigga watts"!

Explanation:

Answer: choice 2

Explanation:

Answer:

Left over mass of hydrogen = 0.06 g

Mass of HCl produced = 12.41 g

Explanation:

Given data:

Mass of H₂ = 0.40 g

Mass of Cl₂ = 12.35 g

Mass of left over reactant = ?

Mass of HCl produced = ?

Solution:

Chemical equation:

H₂ + Cl₂    →     2HCl

Number of moles of H₂:

Number of moles = mass / molar mass

Number of moles = 0.40 g/ 2 g/mol

Number of moles = 0.2 mol

Number of moles of Cl₂:

Number of moles = mass / molar mass

Number of moles = 12.35 g/ 71 g/mol

Number of moles = 0.17 mol

Now we will compare the moles of HCl with H₂ and Cl₂.

                     H₂             :            HCl

                      1               :               2

                   0.2              :           2×0.2 = 0.4

                     Cl₂             :             HCl

                      1               :              2

                    0.17           :            2 × 0.17 = 0.34

Chlorine is limiting reactant.

Mass of HCl produced:

Mass = number of moles × molar mass

Mass = 0.34 mol × 36.5 g/mol

Mass = 12.41 g

Leftover mass of hydrogen:

                          Cl₂               :               H₂

                            1                :                 1

                           0.17            :             0.17

Number of moles of H₂ react with Cl₂  are 0.17.

Moles remain unreacted = 0.2 - 0.17 = 0.03 mol

Mass left over:

Mass = number of moles × molar mass

Mass = 0.03 mol × 2 g/mol

Mass = 0.06 g

The sum of the mass of HCl produced plus the mass of left over reactants is:

Mass of hydrogen = 0.06 g

Mass of HCl  = 12.41 g

Given:

Mass of H₂ = 0.40 g

Mass of Cl₂ = 12.35 g

Mass of left over reactant = ?

Mass of HCl produced = ?

Number of moles of H₂:

Number of moles = mass / molar mass

Number of moles = 0.40 g/ 2 g/mol

Number of moles = 0.2 mol

Number of moles of Cl₂:

Number of moles = mass / molar mass

Number of moles = 12.35 g/ 71 g/mol

Number of moles = 0.17 mol

The moles of HCl with H₂ and Cl₂.                

  H₂             :            HCl              

     1              :               2          

     0.2          :           2×0.2 = 0.4                

    Cl₂             :             HCl            

        1             :              2          

       0.17         :          2 × 0.17 = 0.34

The chlorine is limiting reactant.

Mass of HCl produced:

Mass = number of moles × molar mass

Mass = 0.34 mol × 36.5 g/mol

Mass = 12.41 g

Leftover mass of hydrogen:                

         Cl₂               :               H₂            

              1             :                 1          

               0.17       :             0.17

Number of moles of H₂ react with Cl₂  are 0.17.

Moles remain unreacted = 0.2 - 0.17 = 0.03 mol

Mass left over:

Learn more about "Moles":

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Answer:

What is the question?

Answer:

In addition to aluminium, the main materials in duralumin are copper, manganese and magnesium.

Answer:

The original composition has been varied for particular applications; it may contain about 4 percent copper, 0.5–1 percent manganese, 0.5–1.5 percent magnesium, and, in some formulations, some silicon.

Answer:

D)Gas particles move rapidly and have space between them.

Explanation:

Matter exists in three states namely: solids, liquids and gases. The particles contained in these three states are different from one another. In the gaseous state, the particles are FAR APART from one another i.e. space exists and they move at a very fast rate in contrast to the particles of a liquid, which have less space and move slower.

This rapid movement of gas particles within a less restricted space accounts for the reason why gaseous substances DIFFUSE more quickly than liquids.

Answer:

True, it undergoes a physical change.

Explanation:

A physical change is a change that does not change the chemical makeup of a material. This includes altering its shape.

Answer:

option is (b)

Explanation:

please mark me as brilliant

Answer:

[tex]m_{CO2}=8.33gCO2[/tex]

Explanation:

Hello.

In this case, since the chemical reaction is:

[tex]C_7H_5N_3O_6(s)+\frac{21}{4} O2(g)\rightarrow 7CO_2(g)+\frac{3}{2} N_2(g)+\frac{5}{2} H_2O(l)[/tex]

Thus, since we have the initial moles of TNT:

[tex]n_{TNT}=25.7g*\frac{1mol}{227.13g} =0.113mol[/tex]

And the initial moles of oxygen given the ideal gas equation:

[tex]n_{O_2}=\frac{6.93atm*0.5L}{0.082\frac{atm*L}{mol*K}*298K}=0.142molO_2[/tex]

Given the 1:7 mole ratio between TNT and carbon dioxide and the 21/4:7 mole ratio between oxygen and carbon dioxide, we compute the yielded moles by each reactant:

[tex]n_{CO_2}^{by\ TNT}=0.113molTNT*\frac{7molCO_2}{1molTNT}=0.791molCO_2\\\\ n_{CO_2}^{by\ O_2}=0.142molO_2*\frac{7molCO_2}{21/4molO_2}=0.189molCO_2[/tex]

Thus, since oxygen yields less moles of carbon dioxide than TNT, we infer it is the limiting reactant, therefore, the produced mass of carbon dioxide is:

[tex]m_{CO2}=0.189molCO2*\frac{44.01gCO2}{1molCO2}\\\\m_{CO2}=8.33gCO2[/tex]

Best regards!

Answer:

liquid

Explanation:

correct answer hope it helps

Answer:

It would be 2 and 3

The image shows the structure of an atom, I hope it helps :)

To see the number of atoms of an element in a given molecule we need to multiply stoichiometry to the number that is written on the foot of the element that is stoichiometry. Therefore, the correct option is option 2,3.

Atom is the smallest particle of any element, molecule or compound. Atom can not be further divided. Atoms contains nucleus in its center and electron that revolve around the atom in fixed orbit.

In the nucleus, proton and neutron are present. Electron has -1 charge while proton has +1 charge. Neutron is neutral that is it has no charge. So overall the charge of nucleus is due to only proton, not by neutron. The nucleus contains all the positive charge of an atom. Electrons surround the nucleus and account for the majority of an atom's volume.

Therefore, the correct option is option 2,3.

To know more about atom, here:

https://brainly.com/question/13518322

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Answer:

(a). 132 × 10^-9 s = 132 nanoseconds.

(b)..176.5 pico-seconds.

Explanation:

(a). At one torr, the first thing to do is to find the speed and that can be done by using the formula below;

Speed = [ (8 × R × T)/ Mm × π]^1/2.

Where Mm = molar mass, T = temperature and R = gas constant.

Speed= [ ( 8 × 8.314 × 300)/ 131.293 × π × 10^-3)^1/2. = 220m/s.

The next thing to do now is to calculate for the degree of collision which can be calculated by using the formula below;

Degree of collision = √2 × π × speed × d^2 × pressure/ K × T.

Note that pressure = 1 torr = 133.32 N/m^2 and d = collision diameter.

Degree of collision = √2 × π × 220 × (4.9 × 10^-10)^2 × 133.32/ 1.38 × 10^-23 × 300.

Degree of collision = 7.55 × 10^6 s^-1.

Thus, 1/ 7.55 × 10^6. = 132 × 10^-9 s = 132 nanoseconds.

(b). At one bar;

1/10^5 × 10^3 × 56.65 = 1.765 × 10^-10 = 176.5 pico-seconds.

Answer: C

Explanation:

Answer:

1. Least

2. Most

Answer:

1st one is less 2nd is greater

Explanation:

Answer:

The answer is "[tex]37.45364 \ g[/tex]"

Explanation:

Equation:

[tex]2AgNO_3 (aq) + Na_2CO_3 (aq) \longrightarrow Ag_2CO_3 (s) + 2NaNO_3 (aq)[/tex]

Calculating  the mol of  [tex]AgNO_3[/tex]:

[tex]\to V = 40.0 mL\\\\[/tex]

       [tex]= 40.0 \times 10^{-2} \ L \\\\[/tex]

[tex]\to n = Molarity \times Volume \\\\[/tex]

       [tex]= 0.679 \times 40.0 \times 10^{-2}\\\\= 27.16 \times 10^{-2} \ mol[/tex]

mol of [tex]Ag_2CO_3= \frac{1}{2} \times n\\\\[/tex]

                         [tex]= \frac{1}{2} \times 27.16 \times 10^{-2}\\\\= 13.58 \times 10^{-2}\\\\[/tex]

Calculating the molar mass of [tex]Ag_2CO_3[/tex],:

[tex]= 2\times MM(Ag) + 1 \times MM(C) + 3 \times MM(O)\\\\= 2 \times 107.9 + 1 \times 12.01 + 3 \times 16.0\\\\= 275.81 \ \frac{g}{mol}[/tex]

Calculating the mass of [tex]Ag_2CO_3[/tex],

[tex]m = mol \times molar \ mass[/tex]

   [tex]= 13.38 \times 10^{-2}\ mol \times 2.758 \times 10^2 \ \frac{g}{mol}\\\\= 37.45364 \ g[/tex]

Answer:

Neutral atoms can be turned into positively charged ions by removing one or more electrons.

Explanation:

If there is an atom that has 9 protons and 9 electrons, removing an electron from the atom will gain a postive charge.

Answer:

C

Explanation: I think