A hydrogen atom is an atom of the chemical element hydrogen. The electrically neutral atom contains a single positively charged proton and a single negatively charged electron bound to the nucleus by the Coulomb force. Atomic hydrogen constitutes about 75% of the baryonic mass of the universe.
<span>Why are leaves different colors?</span><span>
The chlorophyll breaks down</span>
The reactivity of a metal is determined by these things.
Firstly, the number of electrons in the outer shell; the fewer the number of electrons in the outer shell, the more reactive the metal.
The number of electron shells also affects reactivity, the more electron shells there are, the more reactive the metal.
