Answer:
Answer is 4
Explanation:
Polar covalent bonding is a type of chemical bond where a pair of electrons is unequally shared between two atoms. ... If the electronegativity of two atoms is basically the same, a nonpolar covalent bond will form, and if the electronegativity is slightly different, a polar covalent bond will form.
Because subatomic particles ARE what make up atoms.
Fireworks changes chemical energy into light energy
Explanation:
21. The given molecule for cracking is tetradecane.
On cracking it forms one mole of decane (C10H22) and two moles of ethene gas.
The chemical equation is shown below:

22. The essential condition for the formation of an ester is the reaction of alcohol and acid in presence of concentrated sulfuric acid.
Thus among the given options, the first option is the correct one.
23. Isomers of butanol are shown below:
It is 2-butanol.
The position of -OH group changes to the second carbon.