Explain why the atomic radii of the elements decrease across Period 3 from sodium to chlorine
As you go across the period from sodium to chlorine, the number of protons in the nucleus increase.As protons are positively charged, they attract the outer electrons; as the number of protons increase, the attraction is greater and therefore the radius decreases.
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All answers ▸When 80.0cm^3 of 0.500 M hydrochloric acid was added to 1.75g of impure CaCO3, not all HCl reacts. The unreacted HCl required 22.4 cm^3 of a 0.500 M solution of NaOH for complete reaction. Calculate percentage by mass of CaCO3 in the impure sample.
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