$$\text{Atomic mass} = \text{protons} + \text{neutrons}$$

$$[\text{H}^+] = 10$$^{-3}$$ \text{M}$$

Question 1

Which of the following best describes the difference between science and non-science according to the study materials?

Accepted Answer

Science relies on repeatable, measurable observations, while non-science relies on untestable explanations.

Question 2

Which equation correctly represents the relationship between atomic mass, protons, and neutrons?

Accepted Answer

$$	ext{Atomic mass} = 	ext{protons} + 	ext{neutrons}$$

Question 3

A radioactive isotope of carbon ($$^{14}	ext{C}) is $$used to date fossils. What property makes it useful for this purpose?

Accepted Answer

It decays at a predictable rate, allowing estimation of age.

Question 4

Which of the following is a trace element essential for thyroid function, and what condition results from its deficiency?

Accepted Answer

Iodine; deficiency causes goiter.

Question 5

Which type of chemical bond involves the sharing of electron pairs between atoms?

Accepted Answer

Covalent bond

Question 6

What is the main reason water molecules are polar?

Accepted Answer

Oxygen is more electronegative than hydrogen, creating partial charges.

Question 7

Which of the following is NOT one of the four emergent properties of water?

Accepted Answer

Water is more dense as a solid than as a liquid.

Question 8

A solution has a pH of 3. What is its hydrogen ion concentration ($$[	ext{H}^+]$$)?

Accepted Answer

$$[	ext{H}^+] = 10$$^{-3}$$ 	ext{M}$$

Question 9

Which functional group is found in amino acids and is responsible for their basic properties?

Accepted Answer

Amino group ($$-	ext{NH}_2)$$

Question 10

Which property of water allows insects to walk on its surface?

Accepted Answer

Surface tension due to hydrogen bonding

Question 11

Which of the following best explains why salt (NaCl) dissolves easily in water?

Accepted Answer

Water's polarity allows it to surround and separate Na$$^+$$ and Cl$$^-$$ ions.

Question 12

Which of the following is a correct statement about biological macromolecules?

Accepted Answer

Proteins are polymers made from amino acid monomers.

Question 13

Which of the following is an example of an isomer important in biology?

Accepted Answer

Enantiomers, which are mirror images important in drug design.

Question 14

Which of the following statements about acids and bases is correct?

Accepted Answer

Acids have a pH less than 7 and donate hydrogen ions ($$	ext{H}^+).$$

Question 15

Which of the following best describes a compound?

Accepted Answer

A substance consisting of two or more elements in a fixed ratio.

Question 16

Which functional group is responsible for the acidic properties of organic molecules?

Accepted Answer

Carboxyl group ($$-	ext{COOH})$$

Question 17

Which of the following best explains why ice floats on water?

Accepted Answer

Ice is less dense than liquid water due to hydrogen bonding.

Question 18

Which of the following is true about valence electrons and chemical reactivity?

Accepted Answer

Atoms with incomplete valence shells are more likely to form bonds.

Question 19

Which property of water is most important for regulating Earth's climate?

Accepted Answer

High specific heat capacity

Question 20

Which of the following correctly describes the formula for calculating pH?

Accepted Answer

$$	ext{pH} = -\log_{10}[	ext{H}^+]$$

General Biology: Foundations, Chemistry, and Biological Molecules

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