In the reaction shown, iron reacts with water to form iron oxide (Fe, 04) and hydrogen gas (H,). 3Fe + 4H20
Fe304 + 4H2
Which of these BEST describes the iron (Fe) reactant?
O
A. molecule
B. ion
o
C. compound
O
D. element

Which is not a characteristic of a heat pump? a. it is used in air conditioners. b. it uses a refrigerant. c. it requires no work. d. it reverses the normal flow of thermal energy.

Aball tossed vertically upward from the ground next to a building passes the bottom of a window 1.8 s after being tossed and passes the top of the window 0.20 s later. the window is 2.0 m high from top to bottom. what was the ball's initial velocity? the unit vector j^ is directed upward. how far is the bottom of the window from the launch position? how high does the ball rise above the launch position?

Lightning is an example of what phenomenon? a release of a large amount of energy an absorption of a large amount of energy a natural electric circuit a natural electric current