Which substance represents a compound?
1. cs2 (s)
2. cs (s)
3. c (s)
4. o2 (9)

Use the table to identify the phase and phase changes of the elements under the given conditions. write the name of the substance, phase, or phase change. when the temperature in a room increases from 25°c to 33°c, changes from a solid to a liquid. in a lab, methane and nitrogen are cooled from -170°c to -200°c. the methane freezes and the nitrogen . when gold is heated to 2,856°c it changes from a liquid to a .

Three cards with holes are arranged in a straight line. a light is shined through the first card’s hole and travels through all three cards. what does this tell you about light rays? a) that light is reflected b) that light is refractive c) that light travels in a straight line d) that light does not travel in a straight line

Using data from seismic waves, geologists have learned that earth’s interior is made up of several