Bio 103 - Chapter 2

Multiple Choice

Which of the following is NOT one of the four states of matter?

• Solid

• Liquid

• Gas

• Foam

Multiple Choice

Which six elements make up 95% of the body weight of organisms?

• Carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur

• Carbon, hydrogen, calcium, sodium, potassium, chlorine

• Oxygen, nitrogen, calcium, iron, magnesium, zinc

• Hydrogen, helium, lithium, beryllium, boron, carbon

Open Ended

Explain the relationship between protons, neutrons, and electrons in an atom and how they determine the properties of an element.

Fill in the Blanks

The atomic number of an element is equal to the number of

in its nucleus.

Multiple Choice

What is the main difference between groups and periods in the periodic table?

• Groups are vertical columns; periods are horizontal rows.

• Groups are horizontal rows; periods are vertical columns.

• Groups and periods are both vertical columns.

• Groups and periods are both horizontal rows.

Multiple Select

Which of the following statements about isotopes are correct?

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

• Isotopes of an element have different atomic masses.

• Isotopes always have the same chemical behavior.

• Isotopes have different numbers of electrons.

Multiple Choice

What is the octet rule in chemistry?

• Atoms are stable with 8 electrons in their outermost shell.

• Atoms are stable with 2 electrons in their outermost shell.

• Atoms are stable with 10 electrons in their outermost shell.

• Atoms are stable with 6 electrons in their outermost shell.

Multiple Select

Which of the following statements about molecules and compounds are correct?

• A molecule is formed when atoms bond together.

• A compound contains at least two different elements.

• A formula tells you the number of each kind of atom in a molecule.

• A compound is always made of the same element.

Fill in the Blanks

An ionic bond forms when electrons are

from one atom to another atom.

Multiple Choice

In a polar covalent bond, what causes the unequal sharing of electrons?

• Difference in electronegativity between atoms

• Atoms have the same number of protons

• Atoms are both metals

• Atoms have identical outer shells

Multiple Choice

What is a hydrogen bond?

• An attraction between a slightly positive hydrogen atom and a slightly negative atom nearby.

• A bond formed by sharing electrons between hydrogen atoms.

• A bond formed by transferring electrons from hydrogen to oxygen.

• A bond that only occurs between two hydrogen atoms.

Multiple Choice

What is the main reason hydrogen bonds are important in biological molecules such as DNA and proteins?

• They provide energy for cellular processes.

• They help maintain the proper structure and function of the molecules.

• They allow molecules to dissolve easily in water.

• They make molecules more acidic.

Multiple Select

Which of the following statements about water's high heat of evaporation are correct?

• It allows animals to cool down through sweating.

• It means water boils at a lower temperature than most liquids.

• It moderates Earth's surface temperature.

• It requires a relatively large amount of heat to break hydrogen bonds.

Fill in the Blanks

A solution contains dissolved substances called

.

Multiple Choice

What property of water allows it to move up a tree from roots to leaves through small tubes?

• High heat capacity

• Cohesion and adhesion

• Low density

• Hydrophobicity

Multiple Choice

Why does ice float on liquid water?

• Ice is more dense than liquid water.

• Ice is less dense than liquid water due to stable hydrogen bonds forming a crystal lattice.

• Ice contains more salt than liquid water.

• Ice molecules are smaller than water molecules.

Multiple Select

Which of the following statements about acids and bases are correct?

• Acids release hydrogen ions (H+) in water.

• Bases take up hydrogen ions or release hydroxide ions (OH−).

• Acids increase the concentration of OH− in solution.

• Bases increase the concentration of H+ in solution.

Multiple Choice

What happens when water ionizes or dissociates?

• It releases equal numbers of hydrogen ions (H+) and hydroxide ions (OH−).

• It forms only hydrogen ions (H+).

• It forms only hydroxide ions (OH−).

• It does not release any ions.

Fill in the Blanks

A substance with a pH of 7 is considered

on the pH scale.

Multiple Choice

Which of the following household substances is most basic according to the pH scale shown?

• Lemon juice

• Milk

• Bleach

• Black coffee

Multiple Choice

Which of the following is NOT a potential impact of acid rain on forests or human-made structures?

• Increased plant photosynthesis

• Damage to plant leaves

• Breakdown of limestone structures

• Degradation of paint on cars

Multiple Choice

What are the four states of matter?

• Solid, liquid, gas, plasma

• Solid, water, air, plasma

• Solid, liquid, vapor, plasma

• Solid, liquid, gas, energy

Multiple Choice

How do buffers help maintain pH stability in living organisms when acids or bases are added?

• By neutralizing acids and bases through chemical reactions

• By increasing the concentration of hydrogen ions

• By removing all water from the solution

• By raising the temperature of the solution