Question

water is a(n) ______ molecule, because the oxygen atom does not share electrons equally with hydrogen, making the oxygen slightly negative and the hydrogen slightly positive.
a nonpolar
b polar
c neutral
question 18
1 point
dna & rna are both examples of which type of organic molecule?
a protein
b nucleic acid
c lipid

Explanation:

• For the first question: A polar molecule has an uneven distribution of electron density. In water (\(H_2O\)), oxygen is more electronegative than hydrogen. So, oxygen pulls the shared electrons closer to itself, creating a partial negative charge (\(\delta -\)) on oxygen and partial positive charges (\(\delta+\)) on hydrogen. Non - polar molecules have an even distribution of electron density (e.g., \(O_2\), \(CO_2\) (though \(CO_2\) has polar bonds, its overall geometry makes it non - polar)), and neutral is too general a term compared to polar which specifically describes the charge separation based on electron sharing.
• For the second question: DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) are composed of nucleotides. Proteins are made of amino acids, and lipids are a diverse group including fats, phospholipids, etc., which have different structures from nucleic acids.

Answer:

1. B. polar
2. B. nucleic acid