In the given examples, Cl2 and CCl4 are non-polar and held by covalent bonds. HI and H2O are polar molecules and held by ionic bonds.
Since covalent bonds are weaker than ionic bonds, Cl2 or CCl4 must have the lowest melting points. Among the two, Cl2 has a lower molecular mass than CCl4, hence Cl2 must have the lowest melting point.
Ans A) Cl2
Answer : An atom is the smallest particle into which an element can be divided and still be the same substance.
Explanation :
Atom : It is the smallest unit of an element. Every atom is composed of a nucleus.
There are three sub-atomic particles present in every atom which are electrons, protons and neutrons.
The nucleus of an atom consist of protons and neutrons.
The electrons are revolve around the nucleus and are bound to the nucleus.
Atomic radius increases as you move left across the periodic table, therefore, potassium will have the largest atomic radius