Magnesium oxide (MgO) is an ionic compound. Magnesium (2,8,2) loses two electrons to become Mg²⁺, and oxygen (2,6) gains two electrons to become O²⁻. This electron transfer forms an electrovalent (ionic) bond. Covalent bonds involve sharing (e.g., H₂O).
Explanation:
Rusting is a chemical change because iron reacts with oxygen and moisture to form a completely new chemical substance, hydrated iron(III) oxide (Fe₂O₃·xH₂O), which has different chemical properties from iron and cannot be easily reversed by simple physical means like heating or cooling.
Explanation:
According to Boyle's Law (P₁V₁ = P₂V₂), pressure and volume are inversely proportional at constant temperature. If the volume is doubled (V₂ = 2V₁), the pressure must be halved (P₂ = P₁/2) to keep the product constant. This demonstrates the inverse relationship between P and V.
Explanation:
Naphthalene sublimes on heating, directly changing to vapor, while sand remains. The naphthalene vapor can be condensed on a cold surface. This technique works for any mixture where one component sublimes (naphthalene, camphor, NH₄Cl). Filtration works for insoluble solids in liquids. Magnetic separation for magnetic ores. Distillation for liquid mixtures.
No comments yet. Be the first to start the discussion!