Explain the following variations in atomic or ionic radii: Ca2 >Mg2 >Be2 For cations with the same charge, ionic radii going down a column, because there is a (n) in the principle quantum number and the average distance from the nucleus of the outer electrons.

Aperfume bottle is dropped in the corner of a room. the odor of the perfume can be detected on the other side of the room. which statement best describes this observation?

Why does earth rotate? because earth is formed from cold gases collapsing due to gravity because the matter in the nebula that formed earth was spinning because earth forms more than 99% of the mass of the solar system because the hydrogen atoms inside the nebula fused to form helium

How can a give a full method for the experiment of separating sand from water by filtration? 1-materials 2-steps 3-conclusion also for water and salt separated by the evaporation or distillation process