Which of the following is the most recent addition to the accepted model of the atom?

atoms are indivisible particles.
protons are located in the nucleus.
electrons form a cloud around the nucleus.
neutrons orbit the nucleus along circular paths.

Each pair of clay balls represents to planetesimals if each plane test molluscum pound of the same material and is separated by the same distance which pair experiences the greatest gravitational attraction

When a spring is compressed, the energy changes from kinetic to potential. which best describes what is causing this change?

100 grams of molten lead (600°c) is used to make musket balls. if the lead shot is allowed to cool to room temperature (21°c), what is the change in entropy (in j/k) of the lead? (for the specific heat of molten and solid lead use 1.29 j/g⋅°c; the latent heat of fusion and the melting point of lead are 2.45 × 104 j/kg and 327°c, respectively.)