Can someone please help FAST im in an exam!

Which diagram shows the correct way to represent an ionic compound of magnesium oxide?

Before it was launched, a helium-filled balloon had a pressure of 201 kpa at a temperature of 27°c. at an altitude of 15,000 m, the pressure had decreased to 2.5 kpa and the temperature had dropped to -14 °c. the volume of the balloon increased to 59.3 m3. what is the original volume of the balloon? 13 m3 0.85 m3 0.077 m3 1.17 m3

Which statement best describes the liquid state of matter? a. it has definite shape but indefinite volume. b. it has definite shape and definite volume. c. it has indefinite shape and indefinite volume. d. it has indefinite shape but definite volume.