Question 1

Which of the following best explains why water (H$$_2O) is $$considered a compound and not an element?

Accepted Answer

Because it can be broken down into simpler substances by chemical means.

Question 2

A nitrogen atom has 7 protons and 7 neutrons. What is its atomic mass in daltons?

Accepted Answer

$$14$$ daltons

Question 3

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 4

If two or more elements are in the same column of the periodic table, what do they have in common?

Accepted Answer

They have the same number of valence electrons.

Question 5

Which of the following best describes a covalent bond?

Accepted Answer

A bond formed by the sharing of electron pairs between atoms.

Question 6

Which of the following is a correct representation of the photosynthesis equation?

Accepted Answer

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

Question 7

Which of the following best explains why carbon is able to form large, complex molecules?

Accepted Answer

Carbon has four valence electrons, allowing it to form up to four covalent bonds.

Question 8

A radioactive isotope of nitrogen has 7 protons, 8 neutrons, and 7 electrons. Which of the following is the correct way to write its atomic symbol?

Accepted Answer

$$^{15}N$$

Question 9

Which of the following statements about chemical reactions is true?

Accepted Answer

Chemical reactions can both make and break chemical bonds.

Question 10

Which of the following best describes an emergent property?

Accepted Answer

A property that arises from the arrangement and interaction of parts within a system.

Question 11

If a molecule of glucose ($$C_6H_{12}O_6$) is completely oxidized in cellular respiration, which of the following is a correct representation of the products?

Accepted Answer

$$6CO_2 + 6H_2O$$

Question 12

Which of the following best explains why hydrogen and oxygen atoms form water molecules?

Accepted Answer

Hydrogen and oxygen share electrons to fill their outer electron shells.

Question 13

Which of the following is a correct statement about valence electrons?

Accepted Answer

Valence electrons determine the chemical properties of an atom.

Question 14

Which of the following best describes the difference between ionic and covalent bonds?

Accepted Answer

Ionic bonds involve the transfer of electrons, while covalent bonds involve the sharing of electrons.

Question 15

Which of the following is a real-world example of an emergent property in biology?

Accepted Answer

The ability of a heart to pump blood, which arises from the coordinated action of many cells.

Question 16

Which of the following best explains why a structural biologist would want to learn the three-dimensional shapes of macromolecules?

Accepted Answer

Because the three-dimensional shape determines the molecule's function.

Question 17

Which of the following is the best explanation for why atoms form chemical bonds?

Accepted Answer

To achieve a stable configuration of electrons in their outer shell.

Question 18

Which of the following is a correct statement about the relationship between structure and function in molecules?

Accepted Answer

The structure of a molecule determines its function.

Question 19

Which of the following best describes the role of enzymes in chemical reactions?

Accepted Answer

Enzymes decrease the activation energy required for a reaction.

Question 20

Which of the following best explains the difference between a trace element and an essential element?

Accepted Answer

Trace elements are required in very small amounts, while essential elements are required in larger amounts.

Chapter 2: Chemical Basis of Life – Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard