These are true and false questions and I want to make sure that I got them right.
1. A water molecule is held together by two single polar covalent bonds. False
2. Because oxygen has a greater electronegativity than hydrogen, water molecules are polar with two partial negative charges near the oxygen atom and one partial positive charge near each hydrogen atom. False
3. Atoms differ in their affinity for neutrons, a property called electronegativity. False
4. In general, electronegativity increases from left to right across each row of the periodic table and also increases down each column. False
5. In a nonpolar covalent bond there is an equal sharing of electrons between two atoms while polar covalent bonds involve an unequal sharing of electrons. True
6. A single molecule of oxygen (O2) is held together by two double nonpolar covalent bonds. True
7. A covalent bond is formed when two atoms share one or more pairs of electrons. True
8. Polar molecules are electrically neutral but the distribution of charge within the molecule is not uniform. True
9. Although C and H differ slightly in electronegativity, this small difference is negligible, and C–H bonds are considered polar. False
10. Of the 4 most common elements found in living organisms, nitrogen has the highest electronegativity and, therefore, the greatest affinity for electrons. False
11. A slightly positive hydrogen atom on one water molecule can attract the slightly negative oxygen atom on a different water molecule, leading to the formation of a hydrogen bond. False
Please check this and I need help with this other question
You arrive late to a biological seminar. However, just as you enter the room, you hear the speaker referring to the "five-prime end" and the "three-prime end" of a macromolecule. Immediately, you know that they are talking about a______
a)carbohydrate.
b)protein.
c)DNA.
d)lipid.
To check the true and false questions:
1. A water molecule is held together by two single polar covalent bonds.
False - A water molecule (H2O) is held together by two single polar covalent bonds—one between oxygen and hydrogen, and another between the two hydrogen atoms.
2. Because oxygen has a greater electronegativity than hydrogen, water molecules are polar with two partial negative charges near the oxygen atom and one partial positive charge near each hydrogen atom.
False - Because oxygen has a greater electronegativity than hydrogen, water molecules are polar with two partial positive charges near each hydrogen atom and one partial negative charge near the oxygen atom.
3. Atoms differ in their affinity for neutrons, a property called electronegativity.
False - Atoms do not differ in their affinity for neutrons. Electronegativity refers to the atoms' affinity for electrons.
4. In general, electronegativity increases from left to right across each row of the periodic table and also increases down each column.
False - In general, electronegativity increases from left to right across each row of the periodic table, but it decreases down each column.
5. In a nonpolar covalent bond, there is an equal sharing of electrons between two atoms, while polar covalent bonds involve an unequal sharing of electrons.
True - In a nonpolar covalent bond, there is an equal sharing of electrons, while in polar covalent bonds, there is an unequal sharing of electrons.
6. A single molecule of oxygen (O2) is held together by two double nonpolar covalent bonds.
True - A single molecule of oxygen (O2) is held together by two double nonpolar covalent bonds.
7. A covalent bond is formed when two atoms share one or more pairs of electrons.
True - A covalent bond is formed when two atoms share one or more pairs of electrons.
8. Polar molecules are electrically neutral, but the distribution of charge within the molecule is not uniform.
True - Polar molecules are electrically neutral, but the distribution of charge within the molecule is not uniform.
9. Although C and H differ slightly in electronegativity, this small difference is negligible, and C–H bonds are considered polar.
False - Although C and H differ slightly in electronegativity, this small difference is negligible, and C-H bonds are considered nonpolar.
10. Of the 4 most common elements found in living organisms, nitrogen has the highest electronegativity and, therefore, the greatest affinity for electrons.
False - Of the four most common elements found in living organisms (carbon, hydrogen, nitrogen, and oxygen), oxygen has the highest electronegativity and the greatest affinity for electrons.
11. A slightly positive hydrogen atom on one water molecule can attract the slightly negative oxygen atom on a different water molecule, leading to the formation of a hydrogen bond.
False - A slightly positive hydrogen atom on one water molecule can attract the slightly negative oxygen atom on a different water molecule, leading to the formation of a hydrogen bond.
Regarding the other question:
The correct answer is c) DNA. The mentioning of the "five-prime end" and the "three-prime end" refers to the orientation of nucleotides within a DNA molecule. DNA strands have a directionality, with one end referred to as the 5' end (five-prime end) and the other as the 3' end (three-prime end). This relates to the numbering of the carbon atoms in the sugar component of the nucleotides in the DNA backbone.