Answer:
The answer to your question is B. metallic
Explanation:
Covalent bonding is a bond between two nonmetals and the difference in electronegativity is between 0 and 1.7. Sodium could not have this kind of bond because is a metal.
Ionic bonding is a bond between a metal and a nonmetal and the difference of electronegativity is higher than 1.7. Sodium can have this kind of bond it is necessary one nonmetal.
Metallic, sodium has a metallic bond because this bond is characteristic of metals.
Answer:
The tank with O₂ weighs more.
Explanation:
We can find the mass of gas using the ideal gas equation.

Considering the pressure (P), volume (V), temperature (T) and ideal gas constant (R) are the same, we can establish that:
m ∝ M
The mass is directly proportional to the molar mass. The molar mass of O₂ (32 g/mol) is higher than the molar mass of N₂ (28 g/mol). Therefore, the tank with O₂ weighs more.
Sharing of electrons always means its a covalent bond, and unequal means it is polar, so it is a polar covalent bond
Explanation:
As per Brønsted-Lowry concept of acids and bases, chemical species which donate proton are called Brønsted-Lowry acids.
The chemical species which accept proton are called Brønsted-Lowry base.
(a) 
is Bronsted lowry acid and
is its conjugate base.
is Bronsted lowry base and
is its conjugate acid.
(b)

is Bronsted lowry base and HCN is its conjugate acid.
is Bronsted lowry acid and
is its conjugate base.
(c)

is Bronsted lowry acid and
is its conjugate base.
Cl^- is Bronsted lowry base and HCl is its conjugate acid.
(d)

is Bronsted lowry acid and
is its conjugate base.
OH^- is Bronsted lowry base and
is its conjugate acid.
(e)

is Bronsted lowry base and OH- is its conjugate acid.
is Bronsted lowry acid and OH- is its conjugate base.