Which of the following electronic transitions in the oxygen atom will result in light emission? A. n​i=​ 1⟶nf​=​ 2
B. n​i=​ 1⟶nf​​=3
C. n​i =3⟶n​f​ =2
D. n​i =2⟶n​f​ =3

Amount of liquid measured in l or lm

Match the mixture with the substance// i really need on this guys (it’s a pic btw)

Which sentence about particles in matter is true? a. atoms are present in solids and liquids but not in gases. b. the particles of matter are in constant motion. c. the same kinds of atoms are found in different elements. d. when a solid changes to a liquid, the sizes of the particles change.