The correct answer is: [A]: ________________________________________________ "Picture I shows a chemical change, because a new substance is formed." __________________________________________________________ Note: "Picture II" is a "physical change" because it is a "phase change"—no "new substance" is form; rather, the same substance changes form. __________________________________________________________
Explanation: In first figure chemical change is taking place. Large iron pipes after exposure to atmosphere resulted in the formation of rust on iron pipes. Rusting happens due to reaction between iron and oxygen with formation of a new substance that is iron(III)oxide which is reddish brown in color.
In second figure there is a change in state of substance which has changed from liquid state to solid state. Only arrangement of molecules has changed. As in liquid state molecule are free to move and weakly associated with each other where as in solid state movement of molecule are restricted.
Because of the peak near the nucleus in the 2s curve there is a higher probability of finding a 2s within 4 Å of the nucleus. In a multi-electron atom an electron in a 2s orbital will have a lower energy than one in a 2p orbital
