Which particle of an element determines what element it is? d. valence electron a. neutron
b. proton
c. electron d. valence electron

If this plastic cup is heated to its melting point, what will eventually happen to all the particles in the plastic? a. the particles will begin to move enough that they slide past each other. b. bonds will form and the liquid will become a solid. c. the spaces between the particles will get smaller. d. the particles will change state and become a crystalline solid.

Are aliens real? justify you’re answer.

In which of these cases are the two wave points considered to be in phase with each other?