PLEASE HELP ME! I am confused on this.

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%

Alloys are used much more than pure metals because they are generally stronger and less likely to react with air or water...

So I would say false

Answer:

Explanation:

1. Cornstarch and water - decantation

2. Iron and sulfur

3. Rice grains and stones - sieving

4. Pebbles and soil - decantation

5. Muddy water - decantation

6. Ground pepper and water - decantation

7. Flour and coarsely ground corn - sieving

8. Needles in a box of beads - using a magnet

9. Sesame seeds in soy sauce -

10. Pebbles and iron nails - using a magnet

11. Fine sand from rocks - sieving

12. Sand from water - filtration

13. Gravel and sand - sieving

14. Salt and iron filings - sieving

15. Pins from assorted buttons - using a magnet

16. Coconut oil from coconut milk - filtration

17. Sand and pebbles - sieving

18. Pasta from water - sieving

19. Sand and thumb tacks - using a magnet

20. Salt solution - filtration

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:

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:

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:

option is (b)

Explanation:

please mark me as brilliant

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

#SPJ2

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:

ecstasy

Explanation:

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:

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: C

Explanation:

Answer: choice 2

Explanation:

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:

the sum of the coefficients in the balanced chemical equation is 9

Explanation:

The computation of the sum of the coefficients in the balanced chemical equation is shown below:

here is the balanced chemical equation

[tex]2NH_4NO_3 \rightarrow 4H_2O)g) + 2N_2(g) + 1O_2(g)[/tex]

Now the sum is

= 2 + 4 + 2 + 1

= 9

hence, the sum of the coefficients in the balanced chemical equation is 9

and, the same is to be considered

Answer:

What is the question?

Answer:

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

Explanation:

when dioxide mixes with water it creates carbonation.

Answer:

liquid

Explanation:

correct answer hope it helps

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:

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:

124.1 g/mol

Explanation:

just facts

Answer:

124.1 g/mol

Explanation:

To calculate formula mass, multiply the subscript of each element in the formula by the element's atomic weight (relative atomic mass) found on the periodic table. The unit for formula mass is either u or Da (Daltons).

electricity from solar panels

Explanation:

All other options produce something after or during the time electricity is made. That something is gas. Not solar

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:

20 moles = (96.7+)

345%20 moles inter = h20

h2+345%20 moles

kalkadanc = jani+CARSORI

564 MOLES

Explanation

we have to plus the moles that we can get the answer and u should now the formula of kalkadanc and just % will get to the correct answer.

i think u may understand and this is the correct answer i had practice this too much