Which of these shows magnesium and oxygen immediately before they join to form an ionic substance?
a. mgo
b. mg + o
c. mg2- + mg2+
d. mg2+ + mg2-

Acatapult is tested by roman legionnaires. they tabulate the results in a papyrus and 2000 years later the archaeological team reads (distances translated into modern units): range = 0.4 km; angle of launch = π/5 rad; landing height = launch height. what is the initial velocity of launch of the boulders if air resistance is negligible?

Excuse ! extra points plus ! super desperate ! the position of an object does not move relative to a reference point. relative to the reference point the object _. a.) is not moving. b.) is moving.

In a heat engine if 1000 j of heat enters the system the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2000 j? 1. write the equation 2.list out your known variables 3.plug the numbers into the equations 4.solve 5.write your solution statement that includes initial energy and final