The diagram shows the box for elements in the periodic table. What is the atomic number of the element shown. A. 27.0 B. 40.0 C.26 D.13

I think it is B.40.0
Because if you do 27+13=40
It will give 0.

Answer: 3

Explanation:

Answer:Physical and chemical laboratory experiments include three primary sources of error: systematic error, random error and human error

Explanation:

When examining the root mean square speed equation, we can see that the changes in temperature (T) and molar mass (M) affect the speed of the gas molecules. The speed of the molecules in a gas is proportional to the temperature and is inversely proportional to molar mass of the gas.

Answer:

All zeros between other significant digits are significant. The number of significant figures is determined by starting with the leftmost non-zero digit. The leftmost non-zero digit is sometimes called the most significant digit or the most significant figure. For example, in the number 0.004205, the '4' is the most significant figure.

Explanation:

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HOPE ITS HELP

GOD BLESS

Answer:

hello,

Good morning have a good day

Answer:

D

Explanation:

the acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of an object

Answer:

Stoichiometric Calculation:

3 NO₂(g) + H₂O (l) → 2 HNO₃(g) + NO(g)

2 moles of HNO₃ is produced from 3 moles of NO₂.

Therefore, By unitary method:

2.30 moles of HNO₃ produced from the moles of NO₂ = [tex] \dfrac{3}{2} \times 2.30 = \bf{3.45 mol}[/tex]

The number of moles of NO₂ that would be required to produce 2.30 moles of HNO₃ in the presence of excess water in the chemical reaction is 3.45 moles

The balance equation is as follows:

3NO₂(g) + H₂O (l) → 2HNO₃(g) + NO(g)

Water molecules is in excess. Therefore, the limiting reagent is Dinitrogen oxide.

The limiting reagent will determine the amount of product produced.

Therefore,

2 moles of HNO₃ needs 3 moles of NO₂

2.30 moles of HNO₃ will need ? moles of NO₂

cross multiply

number of moles of NO₂  = 2.30 × 3 / 2

number of moles of NO₂  = 6.9 / 2

number of moles of NO₂  = 3.45 moles

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Answer:

Sound requires a medium to move through; light does not.

Sound and light are similar in that both are forms of energy that travel in waves.

Explanation:

Sound and light are similar in that both are forms of energy that travel in waves. They both have properties of wavelength, freqency and amplitude. Sound can only travel through a medium (substance) while light can travel through empty space. Sound is a form of mechanical energy caused by vibrations of matter.

Light waves DO NOT require a medium, they travel fastest in empty space; Sound waves REQUIRE a medium, they travel fastest in dense material like solids. Sound is a longitudinal wave.

Answer:

D

Explanation:

Copper has a more positive reduction potential than Hydrogen and is below Hydrogen in the reactivity series. So it can't displace H+ from diluted acids. Therefore Cu doesn't form Cu salt and a gas

Fe, Zn and Mg are above Hydrogen in the electrochemical series and can displace Hydrogen as follows

Fe(s) + 2HCl(aq) ----> FeCl2 +H2 (g)

Mg(s) + 2HCl(aq) ----> MgCl2 (aq) +H2 (g)

So iii is wrong

Zn(s) +2HCl(aq) ----> ZnCl2(aq) +H2 (g)

Explanation:

May kwento po ba yan o yan na talaga

Answer:

chemical reaction

Explanation:

The chemical reaction produces chemical changes to provide energy. Chemical reactions often involve changes in energy due to the breaking and formation of bonds.

Answer:

Since water has a density of 1 gram per cubic centimeter, then the container would need to be 800 cubic centimeters. if this container were a perfect cube, then the length of the side of the container would be equal to the cube-root of 800, which is approximately 9.28 cm to a side, or 3.65 inches to aside.

Answer: it would be the stem and the roots of the plant

Explanation:

Hemoglobin with bound carbon dioxide and hydrogen ions is carried in the blood back to the lungs, where it releases the hydrogen ions and carbon dioxide and rebinds oxygen. Thus, hemoglobin helps to transport hydrogen ions and carbon dioxide in addition to transporting oxygen.

Answer:

Chemical reaction:

2 moles of NO₂ is produced from O₂ moles = 1

Therefore, 2 moles of NO₂ is produced from O₂ moles = [tex]\dfrac{1}{2} \times 13 = \bf{6.5 mol}[/tex]

For 80 % yield no. of moles of O₂ = 6.5 mol

Then for 100% yield no. of moles of O₂ =[tex] \dfrac{6.5}{80\%} =\dfrac{6.5}{\frac{80}{100}} =\dfrac{6.5}{80} \times 100 = \dfrac{650}{80} = \bf 8.125\;mol [/tex]

Answer:

Percentage purity of a substance can be calculated by dividing the mass of the pure chemical by the total mass of the sample, and then multiplying this number by 100.

Explanation:

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Answer:

337.5 g NaCl

Explanation:

.90% saline solution = 90g saline (NaCl)/100mL water (H2O)

1. Use 375 mL to find mass

375 mL × (90 g NaCl/100 mL) = 337.5 g NaCl in 375 mL .9% saline solution

The amount of sodium chloride dissolved in 375 ml of a 0.90% saline solution is 337.5 g.

The concentration can be calculated when we have the molecular formula and its molecular weight. The concentration of the solution is calculated as the weight of a solute divided by the volume of the solution.

The weight/volume percentage of the solution is determined in the following way.

W/v (%) = weight of the solute/Volume of the Solution ( in mL)

Given, the concentration of the saline solution = 0.90 %

0.90 % saline solution means 90 g of NaCl is dissolved in 100 ml of water.

Given, the volume of solution = 375 ml

100 ml of saline solution containing NaCl = 90 g

Then 375 ml of saline solution containing NaCl = 90 ×375/100 = 337.5 g

Therefore, the amount of NaCl is equal to 337.5 g.

Learn more about molar concentration, here:

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Answer:nuclear reaction

Explanation: Nuclear fusion is a type of nuclear reaction where two light nuclei collide together to form a single, heavier nucleus. Fusion results in a release of energy because the mass of the new nucleus is less than the sum of the original masses.

Fusion is the process that powers the sun and the stars. It is the reaction in which two atoms of hydrogen combine together, or fuse, to form an atom of helium. In the process some of the mass of the hydrogen is converted into energy.

Explanation:

this is answer.

Answer:

B

Explanation:

percentage composition helps to determine the percentage of each element in a compound

Answer:

Aluminium ions present's in 65.5mL of 0.210

M All 3solution is Given below-:

Answer and Explanation: 1

The first step is to determine the moles of aluminum ions. This utilizes the volume, molar concentration, and subscripts from the chemical formula of aluminum (III) fluoride as shown.

65.5 mL×1 L1000 mL×0.210 mol AlF31 L×1 mol Al3+1 mol AlF3=0.013755 mol Al3+65.5 mL×1 L1000 mL×0.210 mol AlF31 L×1 mol Al3+1 mol AlF3=0.013755 mol Al3+

To calculate for the number of aluminum ions, we use Avogadro's number as shown.

0.013755 mol Al3+×6.022×1023 ions1 mol Al3+=8.28×1021 ions Al3+.

Itz the ans. of collage ok man.

Answer:

m0.013755

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+

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6.022

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10

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1

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=

8.28

×

10

21

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A

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L

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1

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1000

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×

0.210

m

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A

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1

m

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A

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+

1

Explanation:

The first step is to determine the moles of aluminum ions. This utilizes the volume, molar concentration, and subscripts from the chemical formula of aluminum (III) fluoride as shown.

65.5. To calculate for the number of aluminum ions, we use Avogadro's number as shown.

Answer:

Ga + 6HNO3 → Ga(NO3)3 + 3NO2 + 3H2O

Explanation:

Gallium has an ionic charge of 3+, so three nitrate ions are needed to balance it out.

Given that a single-displacement reaction occurred between two (2) reactants which were placed into a flask,  the potential identities of A, B, and X are: D. A = Mg, B = O, X = Cl.

A single-displacement reaction is also referred to as a single-replacement reaction and it can be defined as a type of chemical reaction wherein a single (one) chemical element of the reacting chemical compound is displaced (replaced) by a similar chemical element.

This ultimately implies that, a single-displacement reaction typically involves a single element displacing another chemical element within a chemical compound.

Note: A potential identity reveals the chemical symbol or name of a chemical element in a particular chemical reaction.

Given the following general reaction of scheme of:

                                     [tex]2AB+2X_2\rightarrow 2AX_2+B_2[/tex]

We would proceed to replace the variables with chemical elements as follows:

                                    [tex]2MgO+2Cl_2\rightarrow 2MgCl_2+O_2[/tex]

Therefore, the potential identities of A, B, and X are:

[tex]A = Mg\\\\B = O\\\\X = Cl[/tex]

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PS: Your question is lacking the necessary information, but I have provided them in the image attached.

Answer:

atomic # 38 or strontium (Sr)

Explanation:

Which ion with a

+2charge has the electron configuration

1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6?

ADD THE ELECTRONS AND ADD 2 MORE  FOR THE +2 CHARGE

so

2 +2 +6 +2 +6 +2 + 10 +  6 +2  

so if it is now neutral (you added 2 e's to ofsetr the +2 charge) it has 38

protons, so it is atomic # 38 or strontium (Sr)

In this case, according to the Raoult's law, we can find the mole fraction of 79 wt% benzene and 21 wt% toluene at 50 °C in the vapor phase as follows:

[tex]y_iP=x_iP_i[/tex]

However, we first have to calculate the mole fractions in the solution as follows (b stands for benzene and t for toluene):

[tex]\\x_b=0.79\frac{g\ benzene}{g\ solution} *\frac{(78.11*x_b+92.14*x_t)}{1mol\ solution} *\frac{1mol\ toluene}{78.11g\ toluene} \\\\x_b=0.79\frac{g\ benzene}{g\ solution} *\frac{78.11*x_b+92.14*(1-x_b)}{1mol\ solution} *\frac{1mol\ toluene}{78.11g\ toluene}\\\\x_b=0.79*(x_b+1.18*(1-x_b))\\\\x_b=0.79x_b+0.932-0.932x_b\\\\x_b=\frac{0.932}{1+0.932-0.79} =0.816\\\\x_t=1-x_b=1-0.816=0.184[/tex]

Next, we calculate the total pressure as follows, according to the Dalton's law:

[tex]P=x_bP_b+x_tP_t=0.816*271mmHg+0.184*91.5mmHg=237.972mmHg[/tex]

Finally, the mole fractions of the vapor phase turn out:

[tex]y_b=\frac{0.816*271mmHg}{237.972mmHg}=0.929\\\\y_t=1- 0.929=0.071[/tex]

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Answer:

The answer is B

B = Petri dishes and sterile droppers

Explanation:

Answer:

it undergoes a chemical change

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The Correct choice is ~ C

They have the same number of electron shells~

Explanation:

option C is correct.....