what is the spectator ion in a reaction
Spectator ion A spectator ion is an ion that exists as a reactant and a product in a chemical equation. A spectator ion can, therefore, be observed in the reaction of aqueous solutions of sodium carbonate and copper(II) sulfate but does not affect the equilibrium:
Rutherford scattering However, the intriguing results showed that around 1 in 8000 alpha particles were deflected by very large angles (over 90°), while the rest passed through with little deflection. From this, Rutherford concluded that the majority of the mass was concentrated in a minute, positively-charged region (the nucleus) surrounded by electrons. When a (positive) alpha particle approached sufficiently close to the nucleus, it was repelled strongly enough to rebound at high angles. The small size of the nucleus explained the small number of alpha particles that were repelled in this way. Rutherford showed, using the method outlined below, that the size of the nucleus was less than about 6986100000000000000♠10−14 m (how much less than this size, Rutherford could not tell from this experiment alone; see more below on this problem of lowest possible size). As an visual example, Figure 1 shows the deflection of an alpha particle by a nucleus in the gas of a cloud chamber.