A volcano valley. Volcanic ash is a good sorce for fertilizer
As you move across a period, the atomic radii decreases. ... As you move across a period, electrons are added to the same energy level while protons are also being added. The concentration of more protons creates a higher effective nuclear charge.
Single-replacement reaction
Larger gases produces more spectral lines than the smaller gases because they have more orbitals in their atoms.
Hydrogen has only one orbital in which an electron orbits. At the excited state, that is, when the electron gains energy, the number of energy level it can transcend is very few. For larger elements, they have more orbitals and when excited, they can move from the ground state to other energy levels at which they produce various unique spectral lines.
The answer is (2). If you recall Rutherford's gold foil experiment, remember that a stream of positively charged alpha particles were shot at a gold foil in the center of a detector ring. The important observation was that although most of the particles passed straight through the foil without being deflected, a tiny fraction of the alpha particles were deflected off the axis of the shot, and some were even deflected almost back to the point from which they were shot. The fact that some of the alpha particles were deflected indicated a positive charge (because same charges repel), and the fact that only a small fraction of the particles were deflected indicated that the positive charge was concentrated in a small area, probably residing at the center of the atom.
