1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
mars1129 [50]
3 years ago
15

33.Platinum crystallizes with the face-centered cubic unit cell. The radius of a platinum atom is 139 pm. Calculate the edge len

gth of the unit cell and the density of platinum in g/cm3.
Mathematics
1 answer:
marin [14]3 years ago
6 0

Answer:

The unit cell edge length is 393.21 pm.

The density of platinum is 21.31 g/cm^3

Step-by-step explanation:

Number of atom in FCC unit cell = Z = 4

Density of platinum =

Edge length of cubic unit cell= a= ?

Radius of the platinum atom, r = 139 pm

r = 0.3535 a

a=\frac{139 pm}{0.3535}=393.21 pm=393.21\times 10^{-10} cm

1 pm = 10^{-10} cm

Atomic mass of Pt(M) = 195.08 g/mol

Formula used :  

\rho=\frac{Z\times M}{N_{A}\times a^{3}}

where,

\rho = density

Z = number of atom in unit cell

M = atomic mass

(N_{A}) = Avogadro's number  

a = edge length of unit cell

On substituting all the given values , we will get the value of 'a'.

d=\frac{4\times 195.08 g/mol}{6.022\times 10^{23} mol^{-1}\times (393.21\times 10^{-10} cm)^{3}}

d= 21.31 g/cm^3.

The unit cell edge length is 393.21 pm.

The density of platinum is 21.31 g/cm^3.

You might be interested in
Write an equation of the ellipse with foci at (0,+12) and vertices at (0,+13)
nekit [7.7K]
 To solve this problem you must apply the proccedure shown below:
 1. You have that the ellipse given as a vertical major axis (a=13), therefore, taking the ellipse with its center at the origin, you have the following equation:
 (y^2/a^2)+(x^2/b^2)=1
 2. You have the distance from the center of the ellipse to the focus:
 c=12, therefore, you can calculate the value of b, the minor radius:
 c^2=a^2-b^2
 b=√(13^3-12^2)
 b=5
 3. Therefore, the equation is:
 a^2=169
 b^2=25
 (y^2/169)+(x^2/25)=1
 The answer is: (y^2/169)+(x^2/25)=1 
6 0
3 years ago
Read 2 more answers
Write and solve a system of linear equations: The larger of two numbers is 18 more than 5 times the smaller. If 3 times the larg
marshall27 [118]

Answer:

8 and -2

Step-by-step explanation:

Let the numbers be l and s.

We have equations:

l = 5s + 18

3l + 4s = 16

Solve for s by substituting l into the second equation:

3(5s + 18) + 4s = 16

15s + 54 + 4s = 16

19s = 16 - 54

19s = -38

s = -38/19

s = -2

Find the value of l:

l = 5(-2) + 18

l = -10 + 18

l = 8

3 0
2 years ago
AQRS is a right triangle.
Paladinen [302]
The third one is correcte
5 0
3 years ago
When you divide a whole number by a whole number( other then one), the quotient is a smaller number?
Ostrovityanka [42]
Yes because division always makes numbers smaller. For example: 12 divided by 4 equals 3.
8 0
3 years ago
Which equation correctly applies the distributive property?
lesantik [10]

Answer: Option 'A' is correct.

Step-by-step explanation:

Since we have given that

Distributive law is defined as

a\times (b+c+d)=a\times b+a\times c+a\times d

According to option'A', we get that

a =- 3

b = 6

c = 0.4

d = 0.08

So, it becomes,

-3\times (6.48)=-3\times 6+(-3)\times 0.4+(-3)\times 0.08

Hence, option 'A' is correct.

8 0
3 years ago
Other questions:
  • A number doubled and has four added to it. The result is divided by three and then added to the product of the original number a
    11·1 answer
  • Can someone please help me with this problem? problem attached. Thank you​
    12·2 answers
  • PAGE 15
    5·1 answer
  • round 0.752 to the nearest tenth explain how you round round 26.48 to the nearest whole number explain how you round round $5.92
    10·2 answers
  • 1. The mechanics at Lincoln Automotive are reborning a 6 in deep cylinder to fit a new piston. The machine they are using increa
    11·1 answer
  • Please help asap! Will give brainliest! Please answer correctly!
    13·1 answer
  • A set of input and output values, such that each input has exactly one output is called a____
    9·2 answers
  • The rate (In mg carbon/m3/h) at which photosynthesis takes place for a species of phytoplankton is modeled by the function 110I
    15·1 answer
  • Order the following from least to greatest.<br> 3.1, 118%, 5/12, 0.06, 2/7
    12·1 answer
  • 2/7 +2/5 find the sum and difrence
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!