Min is asked to balance the equation below.
original: ca3p2 + h2o → ca(oh)2 + ph3
min’s result: ca3p2 + h2o → ca3(oh)2 + ph3
which best describes min’s method for balancing the chemical equation?
it is correct, because now there are three ca atoms on each side of the equation.
it is incorrect, because the identity of the original product has changed.
it is correct, because ca3(oh)2 creates a more stable compound.
it is incorrect, because the subscript “2” should be added instead.

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