Question 1

Which of the following best describes a compound?

Accepted Answer

A substance consisting of two or more different elements combined in a fixed ratio

Question 2

Approximately what percentage of living matter is composed of carbon, hydrogen, oxygen, and nitrogen?

Accepted Answer

96%

Question 3

Which subatomic particle determines the atomic number of an element?

Accepted Answer

Proton

Question 4

If an atom has 8 protons, 8 neutrons, and 8 electrons, what is its atomic mass?

Accepted Answer

$$16$$

Question 5

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 6

Which of the following best describes potential energy in the context of electrons in an atom?

Accepted Answer

The energy that electrons have due to their position relative to the nucleus

Question 7

Which of the following elements is most likely to have a high electronegativity?

Accepted Answer

Fluorine

Question 8

A covalent bond involves:

Accepted Answer

The sharing of electrons between two atoms

Question 9

Which of the following best explains why water molecules are polar?

Accepted Answer

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

Question 10

What 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 11

Which of the following correctly ranks the bond strengths from strongest to weakest?

Accepted Answer

Covalent \u003e Ionic \u003e Hydrogen \u003e Van der Waals

Question 12

A hydrogen bond is a weak bond that forms between:

Accepted Answer

A hydrogen atom covalently bonded to one electronegative atom and another electronegative atom

Question 13

Which of the following is an example of a trace element essential for life?

Accepted Answer

Iron

Question 14

If an atom has 17 protons, 18 neutrons, and 17 electrons, what is its atomic mass and what is the name of this element?

Accepted Answer

Atomic mass = $$35$$, element = Chlorine

Question 15

Which of the following best describes a molecule's valence shell?

Accepted Answer

The outermost electron shell that determines chemical reactivity

Question 16

Which of the following statements about chemical reactions is correct?

Accepted Answer

Chemical reactions involve the making and breaking of chemical bonds

Question 17

In a chemical reaction, the starting materials are called:

Accepted Answer

Reactants

Question 18

Which of the following best describes chemical equilibrium?

Accepted Answer

The forward and reverse reactions occur at the same rate

Question 19

A patient is given a radioactive isotope for medical imaging. Which property of isotopes makes this possible?

Accepted Answer

Some isotopes are unstable and emit radiation as they decay

Question 20

Which of the following scenarios best illustrates the concept of electronegativity?

Accepted Answer

In a water molecule, oxygen attracts shared electrons more strongly than hydrogen

The Chemical Context of Life: Study Notes for General Biology

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