2. A scientist mixed two samples together: a colorless liquid that melts at 12°C and a yellow solid that melts at 390°C. She analyzed the results and found two ending substances. One of the ending substances was a gray solid. This ending substance is made up of the repeating group of atoms shown above. Which of the diagrams to the left shows the repeating groups of atoms that make up the samples the scientist mixed together?

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

In a heat of an engine, if 700 j enters the system, and the piston does 400 j of work what is the final internal (thermal) energy of the system if the initial energy is 1,500 j

Which three statements represent the benefits of performing experiments using computer simulations?