Complete question along with options is attached below,
Answer: Option-B (Ethene) is the correct answer.
Explanation: In given options except option-B (an alkene) all options are example of alkanes.
Reason for reactivity of Alkene:
Alkenes are more reactive than alkanes because it consists of a pi bond. Thus, the electron density in this pi bond lies below or above the bond axis, hence making it more exposed and accessible for incoming electrophile.
Secondly, the
pi bond is weaker than sigma bond and can easily break down. This weakness originates due to less effective overlap of the orbitals forming pi bond as compared to the overlap resulting in the formation of sigma bond.
Therefore, alkenes can add Br₂ through a
electrophillic addition reaction, while alkanes fail to show such reaction.
There are 6.022 x 10^23 copper atoms in a mole.
B. Ca(OH)2 - (Calcium Hydroxide)
Answer:
Valence electrons are the outermost electrons of an atom and are normally the only electrons that participate in chemical bonding. Atoms with full valence electron shells are extremely stable and therefore do not tend to form chemical bonds and have little tendency to gain or lose electrons.