Question 1

Which statement best explains the concept of emergent properties in compounds, as illustrated by the formation of sodium chloride (NaCl) from sodium and chlorine?

Accepted Answer

Emergent properties are the new characteristics that arise when elements combine to form compounds, which are different from those of the individual elements.

Question 2

Which of the following elements makes up the largest percentage of human body mass?

Accepted Answer

Oxygen

Question 3

A radioactive isotope of carbon ($$^{14}C) is $$used in radiometric dating. If the half-life of $$^{14}C is 5$$,730 years, how many years have passed if only 25% of the original $$^{14}C$$ remains in a sample?

Accepted Answer

$$11,460$$ years

Question 4

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

Accepted Answer

A compound consists of two or more elements in a fixed ratio, and has properties different from its constituent elements.

Question 5

Which subatomic particle is responsible for the chemical behavior of an atom?

Accepted Answer

Electron

Question 6

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 7

Which of the following statements about ionic bonds is correct?

Accepted Answer

Ionic bonds result from the attraction between oppositely charged ions after one atom transfers electrons to another.

Question 8

Which type of chemical bond involves the sharing of a pair of valence electrons between two atoms?

Accepted Answer

Covalent bond

Question 9

A water molecule ($$H_2O) is an $$example of which type of covalent bond?

Accepted Answer

Polar covalent bond

Question 10

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

Accepted Answer

They have a full valence shell of electrons.

Question 11

Which of the following is a trace element required by humans in minute quantities?

Accepted Answer

Iron

Question 12

What is the main reason that water molecules can form hydrogen bonds with each other?

Accepted Answer

Water molecules have polar covalent bonds, resulting in partial charges.

Question 13

Which of the following best describes a chemical reaction at equilibrium?

Accepted Answer

The forward and reverse reactions occur at the same rate.

Question 14

Which equation correctly represents the process of photosynthesis?

Accepted Answer

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

Question 15

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

Accepted Answer

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

Question 16

A molecule has the formula $$C_2H_6O. $$Which of the following statements is true?

Accepted Answer

It contains atoms of more than one element in a fixed ratio.

Question 17

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

Accepted Answer

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

Question 18

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

Accepted Answer

They are used as tracers to track atoms through metabolic processes.

Question 19

If a sodium atom ($$Na) $$loses one electron, what is the resulting charge and name of the ion formed?

Accepted Answer

Positive charge; cation

Question 20

Which of the following scenarios best illustrates the importance of molecular shape in biological function?

Accepted Answer

The ability of morphine to bind to endorphin receptors due to its similar shape to natural endorphins.

Chapter 2: The Chemical Context of Life – Study Notes

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드