Spontaneous = exothermic. If it is not spontaneous, it is endothermic. ΔG > 0, which means that the reaction uses energy instead of emitting it.
D. Chemical and Physical Properties
Isotopes are chemical elements with same atomic number (Z), but different mass number (different number of neutrons).
Hydrogen is an element with atomic number 1. It has three isotopes:
1) protium (₁¹H), with mass number 1 (no neutrons).
2) deuterium (₁²H), with mass number 2 (one neutrons, n° = 2 -1, n° = 1).
3) tritium (₁³H), with mass number 3 (two neutrons, n° = 3 -1, n° = 2).
Answer:
Kinetic energy decreases as temperature decreases.
Explanation:
From the description that the system at 80°C has longer arrows, or move faster than the system at 20°C, having shorter actors indicating a slower motion, we can conclude that the kinetic energy of a body depends on its temperature.
If the system at 80°C shows a greater kinetic energy (faster motion of particles) than the system at 20°C, it then implies that decreasing the temperature of the body decreases its kinetic energy.