Answer:
Kr
Explanation:
the element that is in group 18 is noble gasses. the elements are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn), and oganesson (Og).
The basis for Rutherford's Planetary model, was the results he got from experiments.
He observed that most of the alpha particles he fired at a gold foil, passed through the foil, but only few were deflected back. So he concluded that most of the Atom would be empty space, with a positive entity at the center.
B
A quantity that has magnitude and direction.
It is incorrect, because the identity of the original product has changed. Ca3(OH)2 does not exist! It is no longer calcium hydroxide. To balance an equation, you must manipulate the coefficients, a.k.a. the big numbers that go before reactants or products. Subscripts, the little numbers inside the reactants or products, cannot be changed without completely changing the substance.
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