Question 1

Which of the following statements best describes the difference between an element and a compound?

Accepted Answer

An element is a substance that cannot be broken down by chemical reactions, while a compound consists of two or more elements combined in a fixed ratio.

Question 2

Which subatomic particle determines the chemical behavior of an atom?

Accepted Answer

Electron

Question 3

A carbon atom has an atomic number of 6 and an atomic mass of 12.01. How many neutrons does the most common isotope of carbon have?

Accepted Answer

$$12 - 6 = 6$$ neutrons

Question 4

Which of the following best explains why sodium (Na) and chlorine (Cl) form an ionic bond?

Accepted Answer

Sodium donates an electron to chlorine, resulting in oppositely charged ions that attract each other.

Question 5

Which of the following elements is most abundant in the human body by mass?

Accepted Answer

Oxygen

Question 6

What is the maximum number of electrons that can occupy the second electron shell of an atom?

Accepted Answer

$$8$$

Question 7

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 8

Which of the following is a real-life example of a chemical reaction important for life on Earth?

Accepted Answer

$$6 \ \mathrm{CO}_2 + 6 \ \mathrm{H}_2\mathrm{O} \rightarrow \mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6 \ \mathrm{O}_2 ($$photosynthesis)

Question 9

Which of the following statements about isotopes is correct?

Accepted Answer

Isotopes of an element have the same number of protons but different numbers of neutrons.

Question 10

Which type of bond is primarily responsible for the unique properties of water, such as its high boiling point and surface tension?

Accepted Answer

Hydrogen bonds

Question 11

A radioactive isotope has a half-life of 2 years. If you start with 8 grams, how much will remain after 6 years?

Accepted Answer

$$1$$ gram

Question 12

Which of the following best explains why noble gases like neon (Ne) are chemically inert?

Accepted Answer

They have a full valence shell of electrons.

Question 13

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

Accepted Answer

Molecular shape determines how molecules recognize and interact with each other, such as hormones binding to receptors.

Question 14

Which of the following is true about chemical equilibrium?

Accepted Answer

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

Question 15

Which of the following best describes van der Waals interactions?

Accepted Answer

Weak attractions that occur when transient local partial charges attract molecules that are close together.

Question 16

Which of the following is the correct definition of electronegativity?

Accepted Answer

The tendency of an atom to attract electrons in a covalent bond.

Question 17

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

Accepted Answer

The polar water molecules surround and separate the Na$$^+$$ and Cl$$^-$$ ions.

Question 18

Which of the following is an example of a molecule held together by a double covalent bond?

Accepted Answer

$$\mathrm{O}_2$$

Question 19

Which of the following statements about chemical bonds is correct?

Accepted Answer

Covalent bonds involve the sharing of electrons, while ionic bonds involve the transfer of electrons.

Chapter 2: The Chemical Context of Life – Study Notes

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드