Question 1

Which of the following statements best explains why sodium chloride (NaCl) forms an ionic bond rather than a covalent bond?

Accepted Answer

Sodium has a much lower electronegativity than chlorine, resulting in a complete transfer of an electron from sodium to chlorine.

Question 2

Which of the following best describes a trace element?

Accepted Answer

An element required by an organism in minute quantities for proper physiological function.

Question 3

A radioactive isotope of carbon ($$^{14}C) is $$used in PET scans to monitor cancer growth. What property of $$^{14}C$$ makes it useful for this purpose?

Accepted Answer

It emits energy and particles as it decays, which can be detected by imaging instruments.

Question 4

Which of the following best explains why water ($$H_2O) is a $$polar molecule?

Accepted Answer

Oxygen is more electronegative than hydrogen, resulting in unequal sharing of electrons.

Question 5

Which of the following equations correctly represents the photosynthesis reaction?

Accepted Answer

$$6CO_2 + 6H_2O \xrightarrow{sunlight} C_6H_{12}O_6$ + 6O_2$$

Question 6

Which of the following statements about chemical equilibrium is correct?

Accepted Answer

At equilibrium, the forward and reverse reactions occur at the same rate.

Question 7

A molecule of methane ($$CH_4) $$has which of the following types of bonds?

Accepted Answer

Four nonpolar covalent bonds

Question 8

Which of the following best describes the difference between a molecule and a compound?

Accepted Answer

A molecule consists of two or more atoms held together by covalent bonds, while a compound consists of two or more different elements in a fixed ratio.

Question 9

Which of the following is true about van der Waals interactions?

Accepted Answer

They are weak attractions that occur when electrons are unevenly distributed in molecules.

Question 10

If an atom has an atomic number of 8 and a mass number of 18, how many neutrons does it have?

Accepted Answer

10

Question 11

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

Accepted Answer

They have full valence electron shells.

Question 12

Which of the following is a real-world application of radioactive isotopes in medicine?

Accepted Answer

Using radioactive tracers to monitor metabolic processes in PET scans.

Question 13

Which of the following best describes the relationship between atomic number and the identity of an element?

Accepted Answer

The atomic number is the number of protons in the nucleus and determines the element.

Question 14

Which of the following statements about hydrogen bonds is correct?

Accepted Answer

Hydrogen bonds form when a hydrogen atom covalently bonded to one electronegative atom is attracted to another electronegative atom.

Question 15

Which of the following best explains why double bonds are stronger and shorter than single bonds?

Accepted Answer

Double bonds involve the sharing of two pairs of electrons, increasing the bond strength and decreasing the bond length.

Question 16

Which of the following is an example of an emergent property?

Accepted Answer

The ability of sodium and chlorine to form table salt with properties different from either element alone.

Question 17

Which of the following best describes the role of valence electrons in chemical bonding?

Accepted Answer

Valence electrons are found in the outermost shell and determine the chemical behavior of an atom.

Question 18

Which of the following best explains why chemical reactions are considered reversible?

Accepted Answer

Products of the forward reaction can become reactants for the reverse reaction.

Question 19

A gecko can climb smooth walls due to which type of chemical interaction?

Accepted Answer

Van der Waals interactions

Question 20

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

Accepted Answer

Molecules with similar shapes often have similar functions because shape determines how molecules recognize and respond to each other.

Chapter 2: The Chemical Context of Life – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards