Answer:
Covalent bonds usually occur between nonmetals. For example, in water (H2O) each hydrogen (H) and oxygen (O) share a pair of electrons to make a molecule of two hydrogen atoms single bonded to a single oxygen atom. ... Covalent compounds tend to be soft, and have relatively low melting and boiling points.
Answer:
Therefore the equilibrium number of vacancies per unit cubic meter =2.34×10²⁴ vacancies/ mole
Explanation:
The equilibrium number of of vacancies is denoted by 
.
It is depends on
- total no. of atomic number(N)
- energy required for vacancy
- Boltzmann's constant (k)= 8.62×10⁻⁵ev K⁻¹
- temperature (T).
To find equilibrium number of of vacancies we have find N.
Here ρ= 8.45 g/cm³ =8.45 ×10⁶m³
= Avogadro Number = 6.023×10²³
= 63.5 g/mole
g/mole
Here 
=0.9 ev/atom , T= 1000k
Therefore the equilibrium number of vacancies per unit cubic meter,
=2.34×10²⁴ vacancies/ mole
The percent composition of each element can be calculated as follows:
% composition = (mass of element / total mass) * 100
The total mass of the quarter is given to be 5.670 grams
Mass of Cu = 5.198 grams
Mass of Ni = 0.472 grams
Substitute in the above equation to get the mass percentage of each element as follows:
% of Cu = (5.198/5.670) * 100 = 91.675%
% of Ni = (0.472/5.670) * 100 = 8.325%
a. Emma creates a pressure difference allowing the fluid to flow.
