A person walks north for 5 miles, then south for 8 miles, and then north for 6 more miles. The entire trip takes 8 hours. Distance travelled: miles
Displacement: miles
Average speed during trip: miles/hour
Average velocity during trip: miles per hour (north or south?)

I am not sure

Explanation:

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.

"standard molar enthalpy:

h2o ( liquid water ) : - 285.8 kj/mole

h2o ( water vapor ) : - 241.8 kj / mole.

δhrxn = - 241. 8 - ( - 285.8 )= -241.8 + 285.8 = 44.0

answer: 44.0 kj"