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

Question 1

Which of the following statements best describes an isotope?

Accepted Answer

An atom with the same number of protons but a different number of neutrons compared to other atoms of the same element.

Question 2

A neutral atom of sodium (Na) has an atomic number of 11 and a mass number of 23. How many neutrons does it have?

Accepted Answer

$$23 - 11 = 12$$ neutrons

Question 3

Which of the following best explains why noble gases such as neon are chemically inert?

Accepted Answer

Their outermost electron shells are completely filled with electrons.

Question 4

Which type of bond is formed when one atom donates an electron to another atom, resulting in oppositely charged ions that attract each other?

Accepted Answer

Ionic bond

Question 5

A radioactive isotope of carbon, $$^{14}C$$, is used in medical imaging. What property makes it useful as a tracer in metabolic studies?

Accepted Answer

It emits detectable radiation as it decays, allowing its movement to be tracked.

Question 6

Which of the following best describes a polar covalent bond?

Accepted Answer

A bond in which electrons are shared unequally between two atoms, resulting in partial charges.

Question 7

Which of the following is the correct formula for calculating the atomic mass of an atom?

Accepted Answer

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

Question 8

Which of the following statements about chemical reactions is correct?

Accepted Answer

Chemical reactions rearrange the electrons among atoms but do not create or destroy atoms.

Question 9

A molecule of water ($$H_2O) is $$formed by which type of bond between hydrogen and oxygen?

Accepted Answer

Polar covalent bond

Question 10

Which of the following best explains why morphine can mimic the effects of endorphins in the brain?

Accepted Answer

Morphine has a similar molecular shape to endorphins, allowing it to bind to the same receptors.

Question 11

Which of the following is a real-world example of a hydrogen bond's importance in biology?

Accepted Answer

Hydrogen bonds hold the two strands of DNA together in the double helix.

Question 12

If an atom has 17 protons, 18 neutrons, and 17 electrons, what is its atomic number and mass number?

Accepted Answer

Atomic number: $$17$$, Mass number: $$17 + 18 = 35$$

Question 13

Which of the following best describes a van der Waals interaction?

Accepted Answer

A weak attraction that occurs when transient partial charges develop in molecules that are close together.

Question 14

Which of the following is true about the periodic table and the chemical properties of elements?

Accepted Answer

Elements in the same column (group) have similar chemical properties because they have the same number of valence electrons.

Question 15

Which of the following best describes the process of oxidation in a redox reaction?

Accepted Answer

The loss of electrons from a substance.

Question 16

A patient is injected with a radioactive isotope for a PET scan. Which property of the isotope is most important for this medical application?

Accepted Answer

It emits radiation that can be detected by imaging equipment as it decays.

Question 17

Which of the following statements about chemical equilibrium is correct?

Accepted Answer

At equilibrium, the forward and reverse reactions occur at the same rate, and the concentrations of reactants and products remain constant.

Question 18

Which of the following is a correct statement about ions?

Accepted Answer

A cation is a positively charged ion, and an anion is a negatively charged ion.

Question 19

Which of the following best explains why water is a good solvent for many biological molecules?

Accepted Answer

Water is a polar molecule, allowing it to form hydrogen bonds with other polar or charged substances.

Question 20

Which of the following best describes the relationship between molecular shape and biological function?

Accepted Answer

The three-dimensional shape of a molecule determines how it interacts with other molecules, affecting its biological function.

Chapter 2: The Chemical Context of Life – General Biology Study Notes

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