Which of the following reactions is not a replacement reaction?
fe + cuso4 → feso4 + cu
2na + 2h2o → 2naoh + h2
zn + 2hcl → zncl2 + h2
2na + cl2 → 2nacl

An atom of sodium-23 (atomic number = 11) has a positive charge of +1. give this information, how many electrons does it have? how many proteins and neutrons does this atom have

In a heat of an engine, if 700 j enters the system, and the piston does 400 j of work what is the final internal (thermal) energy of the system if the initial energy is 1,500 j

An object displaces 652 ml of water. the volume of the object is: 0.652 cm³ 6.52 cm³ 65.2 cm³ 652 cm³