It allowed him to realize that the mass of an atom is concentrated at its center because the atoms mostly went through the foil but some were deflected. He also realized that an atom probably wasn't just empty space and scattered electron and it had a positive center.
Answer:

Explanation:
Empirical formula of ionic compound formed by two ions
and
is
(for
) of AB (for x = y)
The above empirical formula is in accordance with charge neutrality principle
Here each cation (
and
) can form two ionic compounds by combining with two given anions (
and
).
So the four ionic compounds are: 
Answer:
The spectator ions is:
and 
Explanation:
The equation of reaction between H₂ SO₄ and KOH is:

Rewriting this equation as ionic;
![[2H^{+} + SO^{2-}_4 + 2K^+ +2OH^- \to 2K^+ SO_4^{2-} + 2H_2O ]](https://tex.z-dn.net/?f=%5B2H%5E%7B%2B%7D%20%2B%20SO%5E%7B2-%7D_4%20%2B%202K%5E%2B%20%2B2OH%5E-%20%5Cto%202K%5E%2B%20%20SO_4%5E%7B2-%7D%20%2B%202H_2O%20%5D)
Spectators ions are ions present on both sides of the ionic equation by the same quantity but do not take part in the net reaction.
Answer:
there is no d electron that can be promoted via the absorption of visible light
Explanation:
One of the properties of transition elements is the possession of incompletely filled d orbitals. This property accounts for their unique colours.
The colours of transition metal compounds stem from d-d transition of electrons due to the presence of vacant d orbitals of appropriate energy to which electrons could be promoted.
For elements whose atoms have a d10 configuration, such vacant orbitals does not exist hence their compounds are not colored.
Sometimes, the colour of transition metal compounds stem from ligand to metal charge transfer(LMCT) for instance in KMnO4.
Answer:
I believe the answer is numbers