7. Which of the following is always true when a substance undergoes a phase change? *
O A. The molecules keep moving at the same average speed.
B. The substance becomes a liquid as it heats up.
C. The melting point of the substance changes.
D. The substance is made up of the same type of molecules.

Why is the bond angle in a water molecule less than the bond angle of methane? a. the central oxygen atom in water has two lone pairs of electrons, whereas the central carbon atom in methane has no lone pairs. b. the central hydrogen atom in water has one lone pair of electrons, whereas the central carbon atom in methane has two lone pairs. c. the central oxygen atom in water has four lone pairs of electrons, whereas the central carbon atom in methane has only one lone pair. d. the central oxygen atom exerts more repulsive force on surrounding atoms than the central carbon atom in methane does. reset next

What are the similarities of physical and chemical change ?

Agas has an empirical formula ch4. 0.16g of the gas occupies a volume of 240cm^3 what is the molecular formula of the me anyone who !