(5n,45°) how do I solve this using x and y component

What structural formula represents 4 electrons shared between two atoms?

In a particular chemical reaction, the energy of the reactants is 30 kj and the energy of the products is 5 kj. 
 the maximum energy of the system is 40 kj. sketch a potential energy diagram for this reaction. make sure to label the energy of the reactants, the energy of the products, the activation energy, and the enthalpy change for the reaction.

A0.25 kg arrow is moving at 5 m/s and hits a 0.10 kg apple. the apple sticks to the arrow, and both move to the right together. what is their velocity?