Which electrons are the valence electrons of the atom?
Hel

What can be the use of smoke transformed into liquid?

Which statement describes the appearance of a temperature-vs.-time graph? a horizontal line shows that the temperature increases at a constant rate over time. a vertical line shows that the temperature decreases at a constant rate over time. horizontal lines where the temperature is constant during phase changes connect upward-sloping lines where the temperature increases. horizontal lines where the temperature increases are connected by upward-sloping lines where the temperature is constant for each phase.

What produces wave a)sound b) heats c)transfer of energy d)vibrations