In physical chemistry, the terms body-centered cubic (BCC) and face-centered cubic (FCC) refer to the cubic crystal system of a solid. Each solid is made up simple building blocks called lattice units. There are different layouts of a lattice unit.
It is better understood using 3-D models shown in the picture. A BCC unit cell has one lattice point in the center, together with eight corner atoms which represents 1/8 of an atom. Therefore, there are 1+ 8(1/8) = 2 atoms in a BCC unit cell. On the other hand, a FCC unit cell is composed of half of an atom in each of its faces and 1/8 of an atom in its corners. Therefore, there are (1/2)6 + (1/8)8 = 4 atoms in a FCC unit cell.
Answer:
7213.7kg/m³
Explanation:
Given parameters:
Volume of the metal chunk = 0.131m³
Mass of the metal chunk = 945kg
Unknown:
Density of the metal chunk = ?
Solution :
To solve this problem, density is the mass per unit volume. It is mathematically expressed as;
Density =
So;
Density = = 7213.7kg/m³
Answer: Option (a) is the correct answer.
Explanation:
Entropy is defined as the degree of randomness present in a substance. This means that more randomly the atoms in a substance are moving more will be entropy of the substance.
Entropy of a substance increases with increase in temperature.
For example, when a piece of wood is burned then its molecules will gain kinetic energy and hence, they start to move randomly from one place to another.
As a result, there will occur an increase in its entropy.
Thus, we can conclude that when a piece of wood is burned then its entropy increases.