What do the horizontal portions of the graph represent? When heat is added to or removed from the substance and the temperature remains the same, where is the thermal energy going? Why?

Calculate the enthalpy of the following reaction: 4 b (s) + 3 o2 (g) → 2 b2o3 (s) given the following pertinent information: (a) b2o3 (s) + 3 h2o (g) → 3 o2 (g) + b2h6 (g), δhoa = +2035 kj (b) 2 b (s) + 3 h2 (g) → b2h6 (g), δhob = +36 kj (c) h2 (g) + latex: \frac{1}{2} 1 2 o2 (g) → h2o (l), δhoc = −285 kj (d) h2o (l) → h2o (g), δhod = +44 kj

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 .

What are scientists who study fossils called? ( a ) astronomers. ( b ) biologists. ( c ) geologists. ( d ) paleontologists.