The value of Rth is *

The equilibrium fraction of lattice sites that are vacant in electrum (a silver gold alloy) at 300K C is 9.93 x 10-8. There are

IrinaK [193]

Answer:

the density of the electrum is 14.30 g/cm³

Explanation:

Given that:

The equilibrium fraction of lattice sites that are vacant in electrum = $9.93*10^{-8}$

Number of vacant atoms = $5.854 * 10^{15} \ vacancies/cm^3$

the atomic mass of the electrum = 146.08 g/mol

Avogadro's number = $6.022*10^{23$

The Number of vacant atoms = Fraction of lattice sites × Total number of sites(N)

$5.854*10^{15}$ = $9.93*10^{-8}$ × Total number of sites(N)

Total number of sites (N) = $\dfrac{5.854*10^{15}}{9.93*10^{-8}}$

Total number of sites (N) = $5.895*10^{22}$

From the expression of the total number of sites; we can determine the density of the electrum;

$N = \dfrac{N_A \rho _{electrum}}{A_{electrum}}$

where ;

$N_A$ = Avogadro's Number

$\rho_{electrum} =$ density of the electrum

$A_{electrum}$ = Atomic mass

$5.895*10^{22} = \dfrac{6.022*10^{23}* \rho _{electrum}}{146.08}$

$5.895*10^{22} *146.08}= 6.022*10^{23}* \rho _{electrum}$

$8.611416*10^{24}= 6.022*10^{23}* \rho _{electrum}$

$\rho _{electrum}=\dfrac{8.611416*10^{24}}{6.022*10^{23}}}$

$\mathbf{ \rho _{electrum}=14.30 \ g/cm^3}$

Thus; the density of the electrum is 14.30 g/cm³

7 0

3 years ago

Show that -40 F is approximately equal to -40 C.

V125BC [204]

Answer: Please see below the explanation.

Explanation:

The Celsius (ºC) and Farenheit (ºF), are different temperature scales, but both have identifiable values for two important physical phenomena, water freezing point and water boiling point.

For º C, these are follows:

Freezing Point= 0º C Boiling Point: 100ºC

For º F, we have the following:

Freezing Point= 32º F Boiling Point: 212 ºF

Assuming that all steps (in each scale) between two following values are equal, we have 100 º C between both points in ºC, and 190º in ºF, so degrees in Farenheit are "shorter" than in Celsius, being the relationship, approximately the following:

1 º C = 9/5 ºF.

Taking into account that, by definition, 0ºC = 32º F, we can use the following equations in order to convert ºC to ºF, and viceversa:

ºC = (ºF-32) 5/9

ºF = 32 + 9/5ºC

Now, let's calculate -40ºF, in ºC:

ºC= (-40-32)* 5/9 = -40º C

Let's do the same, converting -40ºC to ºF:

ºF = 32 + (-40)*9/5 = 32 + (-72) = -40ºF.

8 0

3 years ago

Elizabeth has been asked to design a pool umbrella that can withstand wind speeds of up to 30 miles per hour. Now that she under

zlopas [31]

Answer:

The correct option is;

D. She will need to research the problem even more

Explanation:

In other to properly design the pool umbrella that will be reliable and meet the needs of the particular customer, she will need to carry out a basic research about the environment where the pool umbrella is to be used, the presence of other factors that can impact on an idea for the pool umbrella.

She can then proceed to create a concept about the proposed pool umbrella, which is in the form of a paper concept

She will then proceed to carry out a more detailed study based on the paper concept that will consist of concept technology and application as well as functionality.

7 0

4 years ago

Read 2 more answers

20. It is important to keep a copy of your written plan and safety records off-site.

Verdich [7]

Answer:

A

Explanation:

Incase you need to re-read or you need to refresh your memory.

Also, Incase something happens, you will have the rules and guidelines.

4 0

3 years ago

A study of online dating found that when including emoticons in their profiles, response rates for female users _______ by _____

Dvinal [7]

Answer:

Increased, 5%

Explanation:

Recent studies conducted on online dating sites established that the response of female users increased by 5% when emotions are in their profiles even as for male users' response also increased by 8%. Another study also revealed that those who have never used online dating sites and/or mobile dating apps believe that people who use dating apps are desperate.

8 0

3 years ago