Which of the following does NOT contain ionic bond?
A. CH₄
B. KCl
C. CaO
D. NaF
Answer: Option A
Solution (By JKExamLibrary)
CH₄ (methane) has covalent bonds where carbon shares electrons with four hydrogen atoms. CaO (Ca²⁺ O²⁻), KCl, and NaF are ionic compounds formed by electron transfer between a metal and a non-metal. Ionic bonds form when electronegativity difference is large. Covalent bonds typically between non-metals with similar electronegativities.
Explanation:
Salt is obtained by evaporation of seawater in shallow ponds. Water evaporates leaving salt behind. Filtration cannot separate dissolved salt. Distillation would give pure water, not salt. Sublimation for sublimable solids.
Explanation:
Atomic radius decreases across a period because the effective nuclear charge increases while electrons are added to the same shell, pulling the electron cloud closer. Down a group, radius increases due to addition of new shells.
Explanation:
Mendeleev arranged elements in order of increasing atomic mass, grouping those with similar properties. He left gaps for undiscovered elements. Modern table uses atomic number.
No comments yet. Be the first to start the discussion!