How does energy change in these reactions? Is energy needed to start the reactions or is energy given off in the reactions? For each type of reaction, approximately how much
energy is released?

oxygen, selenium, tellurium, and polonium.

they're all from the same group as sulfur (group 16).

what is the average time it took the car to travel 0.25 meters?

⇒ 2.23 seconds

what is the average time it took the car to travel 0.50 meters?

⇒ 3.13 seconds

in the analysis of systems that involve fluid flow, we frequently encounter the combination of properties u and pv.

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.