Tres litros de oxigeno gaseoso a 15 grados centigrados y a presion atmosferica (1atm), se lleva a una presion de 140mm de Hg.¿cual sera ahora el volumen que ocupe el gas si la temperatura no ha variado?

Can someone explain to me how to do this problem ?

The momentum of an isolated system is conserved a) only in inelastic collisions. b) only in elastic collisions. c) in both elastic and inelastic collisions

Which statement best describes copper? a. it has a low resistance and prevents charges from moving freely. b it has a high resistance and allows charges to move freely. c. it has a high resistance and prevents charges from moving freely. d. it has a low resistance and allows charges to move freely