The metal rhenium becomes superconducting at temperatures below 1.4 K. Calculate the temperature at which rhenium becomes superconducting in degrees Celsius.

Answer:

Covalent bonding occurs when electrons are shared between atoms. Double and triple covalent bonds occur when four or six electrons are shared between two atoms, and they are indicated in Lewis structures by drawing two or three lines connecting one atom to another.

Explanation:

Answer:

How can we make use of acids or bases to remove heavy metals from soils? We can remove heavy metals from soil by adding acid and catching the solution that drains through. Acids can react with metals turning metalic compounds which can be dissolved by water and washed away. Improve crop yields?

Explanation:

Answer:

Upwelling! Its the process where the deep cold water rises to the surface! :)

Explanation:

Hope this helps! :)

Answer:

upwelling

Explanation:

Given

Reaction

C+02 = CO2

Required

The equilibrium constant

Solution

The equilibrium constant is the ratio of concentration or pressure between the product and the reactant with each reaction coefficient raised  

The equilibrium constant is based on the concentration (Kc) in a reaction  

pA + qB -----> mC + nD  

[tex]\large {\boxed {\bold {Kc ~ = ~ \frac {[C] ^ m [D] ^ n} {[A] ^ p [B] ^ q}}}}[/tex]

So for the reaction :

C+O₂ ⇔ CO₂

[tex]\tt Kc=\dfrac{[CO_2]}{[C][O_2]}[/tex]

Answer:

The theory of continental drift is most associated with the scientist Alfred Wegener. In the early 20th century, Wegener published a paper explaining his theory that the continental landmasses were “drifting” across the Earth, sometimes plowing through oceans and into each other.

Explanation:

PLEASE MARK ME AS BRAINLIEST

Answer:

The scientist Alfred Wegener.

Explanation:

A scientific control is an experiment or observation designed to minimize the effects of variables other than the independent variable. This increases the reliability of the results, often through a comparison between control measurements and the other measurements.

Answer:

only 1 parent is needed! and the offspring is a identical copy of the parent

Answer:

[tex]m_{Fe(OH)_3} = 0.891gFe(OH)_3[/tex]

Explanation:

Hello!

In this case, given the chemical reaction:

[tex]3NaOH(aq)+Fe(NO_3)_3(aq)\rightarrow 3NaNO_3(aq)+Fe(OH)_3(s)[/tex]

In such a way, given the volumes and molarities of each reactant, we can compute the moles of produced iron (III) hydroxide by each of them, via the 3:1 and 1:1 mole ratios:

[tex]n_{Fe(OH)_3}^{by\ NaOH}=0.0500L*0.500\frac{molNaOH}{L}*\frac{1molFe(OH)_3}{3molNaOH} =0.00833molFe(OH)_3\\\\n_{Fe(OH)_3}^{by\ Fe(NO_3)_3}=0.0750L*0.200\frac{molFe(NO_3)_3}{L}*\frac{1molFe(OH)_3}{1molFe(NO_3)_3} =0.0150molFe(OH)_3[/tex]

It means that the sodium hydroxide is the limiting reactant and 0.00833 moles of iron (III) hydroxide are produced; thus, the required mass is:

[tex]m_{Fe(OH)_3}=0.00833molFe(OH)_3*\frac{106.87gFe(OH)_3}{1molFe(OH)_3} \\\\m_{Fe(OH)_3} = 0.891gFe(OH)_3[/tex]

Best regards!

Answer:

Establish and Use a Secure Connection

Use SSH Keys Authentication

Secure File Transfer Protocol

Secure Sockets Layer Certificates

Use Private Networks and VPNs

Explanation:

Answer:

radiation

Explanation:

hope this helps!

Answer:

the blanket of gases that surrounds Earth and some other planets

Explanation:

The best definition of the atmosphere is that it is a portion of the earth that is a made up of a blanket of gases.

The volume required : 0.2 L

Given

500ml of 0.1M potassium dichromate (vii)

0.25 solution

Required

The volume

Solution

We can use dilution formula :

M₁V₁=M₂V₂

M₁ = 0.25

M₂ = 0.1

V₂ = 500 ml = 0.5 L

The initial volume taken :

V₁=(M₂V₂)/M₁

V₁=(0.1 x 0.5)/0.25

V₁=0.2 L

Answer:

Glucose molecules

Explanation:

The question is incomplete, the complete question is;

Silicon has three naturally occurring isotopes with thefollowing masses and natural abundances:

Isotope Mass ({\rm amu}) Abundance (%)

{\rm Si}-28 27.9769 92.2

{\rm Si}-29 28.9765 4.67

{\rm Si}-30 29.9737 3.10

Calculate the atomic mass of silicon.

Answer:

28.09 amu (to four significant figures)

Explanation:

Given that;

Isotope Mass  Abundance (%)

Si-28 27.9769 92.2

Si-29 28.9765 4.67

Si-30 29.9737 3.10

So we now have;

Relative atomic mass of silicon;

(27.9769  ×  0.9218)  +  (28.9765  ×  0.0471)  +  (29.9738  ×  0.0312)

25.789 + 1.365 + 0.9351 = 28.09 amu (to four significant figures)

Answer:

double replacement

Explanation:

The reaction shown is a double replacement reaction.

It is also known as double decomposition or metathesis reaction.

In such a reaction, there is an actual exchange of partners to form new compounds.

One of the following is the driving force for such reaction:

Considering the solution of mole fraction, molality and molarity, you obtain that:

(a) the mole fraction of thiophene in the solution is 0.039.

(b) the molality of thiophene in the solution 0.4429 [tex]\frac{moles}{kg}[/tex].

(c)  the molarity of thiophene in the solution is 0.373[tex]\frac{moles}{L}[/tex].

You know that:

The molar fraction is a way of measuring the concentration that expresses the proportion in which a substance is found with respect to the total moles of the solution.

Being the molar mass of each compound equals to:

the number of moles of each compound can be calculated as:

The total moles is obtained from the addition of the moles of the solute (C₄H₄S) and the solvent (C₇H₈):

total moles = moles C₄H₄S + moles C₇H₈ = 0.096 moles + 2.35 moles = 2.45 moles

Then, the mole fraction of thiophene in the solution can be calculated as:

[tex]mole fraction of thiophene=\frac{0.096 moles}{2.45 moles}[/tex]

Solving:

mole fraction of thiophene= 0.039

Finally, the mole fraction of thiophene in the solution is 0.039.

Molality is the ratio of the number of moles of any dissolved solute to kilograms of solvent.

The Molality of a solution is determined by the expression:

[tex]Molality=\frac{number of moles of solute}{kilograms of solvent}[/tex]

In this case, you know:

Replacing:

[tex]Molality C_{4} H_{4}S =\frac{0.096 moles}{0.21675 kg}[/tex]

molality C₄H₄S= 0.4429 [tex]\frac{moles}{kg}[/tex]

Finally, the molality of thiophene in the solution 0.4429 [tex]\frac{moles}{kg}[/tex].

Molarity is the number of moles of solute that are dissolved in a certain volume and is determined by the following expression:

[tex]Molarity=\frac{number of moles of solute}{volume}[/tex]

Assuming that the volumes of solute and solvent are additive, you can add the volume of C₄H₄S and C₇H₈.

But first, you need yo know the volume of C₄H₄S, which can be calculated from the mass and density:

[tex]Volume C_{4} H_{4}S =8.10 grams\frac{1 mL}{1.065 grams}[/tex]= 7.606 mL= 0.007606 L

Then, the total volume of the solution is calculated as:

total volume of the solution= volume C₇H₈ + volume C₄H₄S

total volume of the solution= 0.250 L + 0.007606 L = 0.257606 L

So, the molarity of thiophene in the solution can be calculated as:

[tex]Molarity C_{4} H_{4} S=\frac{number of moles of C_{4} H_{4} S}{totalvolumeof the solution}[/tex]

Replacing:

[tex]Molarity C_{4} H_{4} S=\frac{0.096 moles}{0.257606 L}[/tex]

Solving:

Molarity C₄H₄S= 0.373 [tex]\frac{moles}{L}[/tex]

Finally, the molarity of thiophene in the solution is 0.373[tex]\frac{moles}{L}[/tex].

In summary, you get:

(a) the mole fraction of thiophene in the solution is 0.039.

(b) the molality of thiophene in the solution 0.4429 [tex]\frac{moles}{kg}[/tex].

(c)  the molarity of thiophene in the solution is 0.373[tex]\frac{moles}{L}[/tex].

Learn more about

Answer:

Calcium

Explanation:

The symbol for the element with a mass number of 27 is actually Al for Aluminum instead of Co for Cobalt. Mass number refers to atomic mass, not atomic number.

Aluminum has an atomic mass of 26.982 or 27.

The letters to unscramble are I, M, C, Al, U, and C.

The mystery element is Calcium.

Hope that helps.

Answer:

0.089

Explanation:

2.5/ 14= .178 then 0.178/ 2 again and you get 0.089

The moles of nitrogen in 2.5 grams of the compound is 0.089 moles. Thus option A is correct.

Moles can be calculated as the ratio of mass to molecular mass.

Moles = [tex]\rm \dfrac{weight}{molecular\;weight}[/tex]

The mass of Nitrogen = 14 g/mol

The mass of diatomic nitrogen = 2 [tex]\times[/tex] mass of nitrogen

The mass of diatomic nitrogen = 2 [tex]\times[/tex] 14 g/mol

The mass of diatomic nitogen = 28 g/mol

The molecular weight of Nitrogen = 28g/mol

Given, the mass of Nitrogen = 2.5 g

Moles of nitrogen = [tex]\rm \dfrac{2.5}{28}[/tex]

Moles of Nitrogen = 0.089 moles.

The moles of nitrogen in 2.5 grams of the compound is 0.089 moles. Thus option A is correct.

For more information about a mole, refer to the link:

https://brainly.com/question/21898305

Answer:

Potassium

Explanation:

The symbol for the element with a mass number of 169 is Tm for Thulium.

The letters to unscramble are S, Si, Tm, P, Au, and o.

The mystery element is Potassium.

Hope that helps.

Answer:

In atomic number

And size

And nature of each (metal, non, or metalloide)

[tex]\Large \boxed{\sf by \ their \ properties}[/tex]

Every element has a set of particular characteristics. Each has a unique atomic and mass number because they contain a different ratio of protons and neutrons. The number of protons in an element mirrors the element's atomic number. The mass number equals the sum of the element's protons and neutrons.

According to increasing atomic numbers, chemical elements get organized. Periods and groups are the names of the horizontal rows and vertical columns, respectively. The chemical characteristics of elements within the same group are comparable due to their similar valency and number of outer electrons.

Answer:

A. Theoretical yield of C is 9.03 g

B. Mass of B consumed is 5.53 g

Explanation:

A. Determination of the theoretical yield of C.

Actual yield of C = 6.5 g

Percentage yield of C = 72.%

Theoretical yield of C =?

Percentage yield = Actual yield /Theoretical yield × 100

72% = 6.5 / Theoretical yield

72 / 100 = 6.5 / Theoretical yield

Cross multiply

72 × Theoretical yield = 100 × 6.5

72 × Theoretical yield = 650

Divide both side by 72

Theoretical yield = 650 / 72

Theoretical yield = 9.03 g

Therefore, the theoretical yield of C is 9.03 g

B. Determination of the mass of B consumed.

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

A + B —> C

Mass of A = 3.5 g

Mass of C = 9.03 g

Mass of B =?

A + B = C

3.5 + B = 9.03

Collect like terms

B = 9.03 – 3.5

B = 5.53 g

Thus, the mass of B consumed in the reaction is 5.53 g

Answer:

XY4Z2- dsp2

XY4Z- sp3d

XY5Z- sp3d2

XY2Z3- sp3d

XY2Z- sp2

XY3Z- sp3

XY2Z2- sp3

XY3Z2- sp3d

XY2 - sp

,XY3- sp2

XY4- sp3

,XY5- sp3d

XY6- sp3d2

Explanation:

In the answer box I have shown the hybridization patterns of the various arrangement of bond pairs and lone pairs.

Hybridization was put forward to explain the shapes of molecules under the valence bond theory. All molecules having the same hybridization pattern are based on the same geometry. Deviations from the expected geometry may arise due to the presence of lone pairs.

Answer:

Read this section of the text:

These raptors eat primarily flying insects, so they do most of their hunting on the wing.

What does primarily mean in this sentence?

Explanation:

I'm bored

Answer:

0.0

Explanation:

Answer:

no stranger danger!

Explanation:

nice profile pic tho

Answer - B Atoms in the original substances are arranged in a different way to make new substances

The mole fraction of oxygen gas : 0.381

Given

2.31 atm Oxygen

3.75 atm Hydrogen

Required

The mole fraction of Oxygen

Solution

Dalton Law's of partial pressure

P tot = P₁ + P₂ + ..Pₙ

Input the value :

P tot = P O₂ + P H₂

P tot = 2.31 atm + 3.75 atm

P tot = 6.06 atm

The mole fraction of O₂ (X O₂):

P O₂ = X O₂ x P tot

X O₂ = P O₂ / P tot

X O₂ = 2.31 /6.06

X O₂ = 0.381

The mole fraction of oxygen gas in the given mixture of oxygen and hydrogen gas is 0.381.

If the details is present in terms of partial pressure then by using the below equation, we can calculate the mole fraction as:

p = (x)(P), where

p = partial pressure

P = total pressure

x = mole fraction

Total pressure of the mixture will be calculated by adding the partial pressure of oxygen and hydrogen gases as:

P = 2.31 + 3.75 = 6.06 atm

Now mole fraction of oxygen will be calculated as:

x = 2.31 / 6.06 = 0.381

Hence mole fraction of oxygen is 0.381.

To know more about mole fraction, visit the below link:
https://brainly.com/question/1553736

Answer:

6 electrons

Explanation:

The principal quantum number n; describes the energy level and here, it is 2.

The azimuthal or secondary quantum number l is given as 1, we are describing the p-orbital

The magnetic quantum number is -1, and we have 3 sub-orbitals here:

   It is a 2p-suborbital

So; in each sub orbital we have 2 electrons

The number of electrons that can be described here  =  2 x 3 = 6 electrons.