Pls help needs to be done soon thxs Valence Electrons: definition, how they increase across the Periodic table (periodic trend), and how they relate to both ionic and covalent bonding

Why did ptolemy have to introduce multiple circles of motion for the planets instead of a single, simple circle to represent the planetâs motion around the sun?

These models show the electron structures of two different nonmetal elements. which element is likely more reactive, and why? element 1 is more reactive because it has fewer electron shells and is toward the top of its group on the periodic table. element 1 is more reactive because it has more electrons in its valence shell and is farther to the right on the periodic table. element 2 is more reactive because it does not have a valence shell close to the nucleus, so it will attract electrons. element 2 is more reactive because it does not have a full valence shell, so it will attract electrons.

An automobile of mass 2000 kg moving at 30 m/s is braked suddenly with a constant braking force of 10000 n. how far does the car travel before stopping?