Question

In: Chemistry

Assuming atoms of radius of 1.00 Å and atoms just touching one another, calculate the percentage...

Assuming atoms of radius of 1.00 Å and atoms just touching one another, calculate the percentage of the volume taken up in a face-centered cubic unit cell by those atoms.

Expert Solution

Ans:

In FCC, along with the atoms in the 8 corner of a unit cell, we will have 1 atom sitting at the centre of each face.
Atoms present at the corner will contribute 1/8 to unit cell
Atoms present at the centre of face contribute 1/2 to unit cell
A cube will have 8 corners and 6 faces.
Number of atoms per unit cell of FCC, Z = (8 x 1/8) + (6 x 1/2) = 4
In FCC, atoms along the face diagonal touch each other.

In triangle ABC, using Pythagorean theorem we can write

AC² = AB² + BC²

F² = a² + a² = 2a²

We can also see from the diagram that, F = 4r. So,

(4r)² = 2a²

16r² = 2a²

a =

Packing efficiency = x 100

Packing efficiency = x 100 = x 100

Packing efficiency = 74%

74% of the cube volume is occupied by the atoms

queen_honey_blossom answered 3 years ago

Two 0.60 kg basketballs, each with a radius of 10 cm, are just touching. Ignore any...

Two 0.60 kg basketballs, each with a radius of 10 cm, are just touching. Ignore any other gravitational interactions. (a) How much energy is required to change the separation between the centers of the basketballs to 1.0 m? _____ J (b) How much energy is required to change the separation between the centers of the basketballs to 10 m? _____ J As usual, if you don't draw the picture, label distances, you'll use the formula incorrectly.

For the given elements, calculate the number of atoms in 1.00 gram of that element. How...

For the given elements, calculate the number of atoms in 1.00 gram of that element. How many atoms of magnesium are in 1.00 gram? How many atoms of iron are in 1.00 gram? How many atoms of argon are in 1.00 gram?

The interaction of one photon with another can be understood by assuming that each photon can...

The interaction of one photon with another can be understood by assuming that each photon can temporarily become a “virtual” electron-positron pair in free space, and the respective pairs can then interact electromagnetically. (a) How long does the uncertainty principle allow a virtual electron-positron pair to exist if h 2mc2, where m is the electron mass? (b) If h 2mc2, can you use the notion of virtual electron-positron pairs to explain the role of a nucleus in the production...

Do you think the media is too biased one way or another? Assuming that there is...

Do you think the media is too biased one way or another? Assuming that there is a bias, how do you think we should reduce that bias as a society? How do you avoid developing a bias in your news sources?

There are two methods to calculate the allowance. One is the percentage of sales method that...

There are two methods to calculate the allowance. One is the percentage of sales method that determines the amount based on multiplying the expected percentage of uncollectibles by the net credit sales. There is also the aging of receivables method. Can you tell me what that is?

T2. Two restaurants compete against one another for a pool of 10,000 local potential patrons. Assuming...

T2. Two restaurants compete against one another for a pool of 10,000 local potential patrons. Assuming people tend to choose between the two restaurants at random and independently, use a binomial model to find how many seats S our restaurant should have such that the probability of turning a customer away due to being at capacity is less than 1%.

Calculate to one decimal place the percentage composition of: a) KMnO4 b) If you have 25,490...

Calculate to one decimal place the percentage composition of: a) KMnO4 b) If you have 25,490 grams of aluminum oxide, how much aluminum do you have in the compound?

7. Calculate the pressure that CCl4 will exert at 40 °C if 1.00 mole occupies 28.0 L assuming that CCl4 behaves like a real gas.

7. Calculate the pressure that CCl4 will exert at 40 °C if 1.00 mole occupies 28.0 L assuming that CCl4 behaves like a real gas. (Values for the van der Waals constants are a = 19.7 L2atm/ mol2, b = 0.1281 L/mol.)8. HCN can be formed by the reaction below:NaCN(s) + HCl(aq) à HCN(g) + NaCl(aq)What mass of NaCN is required to make 2.25 L of HCN at 30°C and 748 mmHg? (3 points)

Calculate the present value (PV ) of a cash inflow of $500 in one year, and a cash inflow of $1,000 in 5 years, assuming a discount rate of 15%.

In the energy pyramid below, calculate the amount of energy that is passed up from one trophic level to the next, assuming only 10% of the energy from the previous level is available for the next level.

In the energy pyramid below, calculate the amount of energy that is passed up from one trophic level to the next, assuming only 10% of the energy from the previous level is available for the next level. For each trophic level, circle all the words that apply to identify each organism as either a producer or consumer and as either an autotroph or a heterotroph. If the organism could be considered a predator and/or prey, circle those words also. Questions 1. Assume...