Why is liquid water more dense than ice?

Why is liquid water more dense than ice?

Which of the follow are false?

I. Three phases can coexist at the triple point.

II. It is not possible for ice to transition directly to water vapor without become a liquid first.

III. The slope of the ice/water phase curve is positive

IV. Distinct phases are not achievable above the critical point

Which of the follow are false?

I. Three phases can coexist at the triple point.

II. It is not possible for ice to transition directly to water vapor without become a liquid first.

III. The slope of the ice/water phase curve is positive

IV. Distinct phases are not achievable above the critical point