An ionic bond forms between sodium and chlorine when the sodium atoms electrons.

loses

Explanation:

Ionic bond is formed by transfer of electrons from metals to non metals.

Electronic configuration of sodium:

Sodium atom will loose one electron to gain noble gas configuration and form sodium cation with +1 charge.

Electronic configuration of chlorine:

Chlorine atom will gain one electron to gain noble gas configuration and form chloride ion with -1 charge.

In sodium chloride the lost electron from sodium metal gets transferred to chlorine atom.

d₁ = displacement of tern from arctic to antarctic = 11000 miles

d₂ = displacement of tern from antarctic to arctic =   - 11000 miles

d = total displacement for the journey

total displacement for the journey is given as

d = d₁ + d₂

d = 11000 + (-11000)

d = 0 miles

t₁ = time of travel from arctic to antarctic = 3 months = 3 x 30 days = 90 days

t₂ = time of travel from antarctic to arctic = 3 months = 3 x 30 days = 90 days

t = total time of travel

total time of travel is given as

t = t₁ + t₂

t = 90 + 90

t = 180 days

average velocity is given as

average velocity = total displacement/ total time

v = d/t

v = 0/180

v = 0 miles/day

if the person is shown to have +90n, then ans is -10n.

if the person is shown to have -90n, then ans is +10n.