Choose the correct way to complete the sentences to explain technological developments in the twentieth century. and are technological developments of the twentieth century.

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.

lol idk man i guess u gotta ask bill nye the science guy

the crab is multicellular

the pond organism is unicellular