Assertion :In molluscs, feather-like gills are present in mantle cavity. Reason: These gills have respiratory and excretory functions.
Assertion: Be and Al have similar properties.
Reason: Be2+ and Al3+ have nearly the same charge/volume ratios and similar polarising power.
ASSERTION: n-Pentane and n-Hexane belong to a homologous series.
REASON: n-Pentane and n-Hexane belong to the same class of hydrocarbons and they differ by a - CH2 - group.
Assertion – The non-fusible impurities present in iron ore are removed by CaCO3 .
Reason: CaCO3 which decomposes into CaO and CO2. The CaO formed reacts with SiO2 to remove silica
Assertion : Two electrons of helium atom are placed in only one shell but three electrons of lithium need two shells. Reason: A shell can have maximum 2n2 electrons.
Assertion: The impurities such as SiO2 present in iron ore is removed by CaCO3. Reason: CaO formed by decomposition of CaCO3 reacts with SiO2 to form slag.