It takes so much heat to melt ice or evaporate water because extra energy is required to break the hydrogen bonds between water molecules.

<h3>Hydrogen bond</h3>

Hydrogen bonding is an electrostatic force of attraction between a hydrogen atom found between a pair of other atoms having a high affinity for electrons.

Hydrogen bonds cause water to be exceptionally attracted to each other creating cohesion.

It takes so much heat to melt ice or evaporate water because extra energy is required to break the hydrogen bonds between water molecules.

Find out more on Hydrogen bond at: brainly.com/question/12798212

4 0

2 years ago

Molybdenum (Mo) has a body centered cubic unit cell. The density of Mo is 10.28 g/cm3. Determine (a) the edge length of the unit

ser-zykov [4K]

Answer:

For a: The edge length of the unit cell is 314 pm

For b: The radius of the molybdenum atom is 135.9 pm

Explanation:

For a:

To calculate the edge length for given density of metal, we use the equation:

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

where,

$\rho$ = density = $10.28g/cm^3$

Z = number of atom in unit cell = 2 (BCC)

M = atomic mass of metal (molybdenum) = 95.94 g/mol

$N_{A}$ = Avogadro's number = $6.022\times 10^{23}$

a = edge length of unit cell =?

Putting values in above equation, we get:

$10.28=\frac{2\times 95.94}{6.022\times 10^{23}\times (a)^3}\\\\a^3=\frac{2\times 95.94}{6.022\times 10^{23}\times 10.28}=3.099\times 10^{-23}\\\\a=\sqrt[3]{3.099\times 10^{-23}}=3.14\times 10^{-8}cm=314pm$