WorksheetsChapter 2. The Chemical Foundation of Life 1 - 30
Total questions: 100
Worksheet time: 50mins
Matter and elements are defined as:
Matter is anything that has mass and takes up space; elements are pure substances made of only one kind of atom.
Matter is a type of energy; elements are mixtures of different substances.
Matter is only found in solid form; elements are always gases.
Matter and elements are both types of compounds.
The interrelationship between protons, neutrons, and electrons is best described as:
Protons and neutrons are found in the nucleus, while electrons orbit around the nucleus.
Protons and electrons are found in the nucleus, while neutrons orbit around the nucleus.
Neutrons and electrons are found in the nucleus, while protons orbit around the nucleus.
All three particles are found orbiting the nucleus.
Electrons can be donated or shared between atoms in which of the following ways?
Through ionic and covalent bonding
Through metallic and hydrogen bonding only
By forming only covalent bonds
By sharing protons instead of electrons
Naturally occurring elements combine to create which of the following, in order from simplest to most complex?
Molecules, cells, tissues, organ systems, organisms
Cells, molecules, tissues, organ systems, organisms
Tissues, molecules, cells, organ systems, organisms
Organ systems, tissues, cells, molecules, organisms
The properties of water that are critical to maintaining life include:
Cohesion, high specific heat, solvent abilities, and density as a solid
High melting point, low surface tension, and being non-polar
Inability to dissolve substances, low heat capacity, and high viscosity
Lack of hydrogen bonding, low boiling point, and being hydrophobic
Water is an excellent solvent because:
it is a polar molecule and can dissolve many substances.
it is nonpolar and does not interact with other molecules.
it cannot dissolve salts or sugars.
it only dissolves gases.
Examples of water's cohesive and adhesive properties include:
Cohesion: water droplets forming on a leaf; Adhesion: water climbing up a paper towel
Cohesion: water dissolving salt; Adhesion: water evaporating
Cohesion: water freezing; Adhesion: water boiling
Cohesion: water mixing with oil; Adhesion: water repelling plastic
The role of acids, bases, and buffers in homeostasis is to:
maintain the pH balance in the body
increase the acidity of blood
eliminate all bases from the body
prevent the formation of buffers
Carbon is important for life because:
it forms the backbone of organic molecules essential for living organisms.
it is the most abundant element in the universe.
it is only found in non-living things.
it cannot form bonds with other elements.
The role of functional groups in biological molecules is to:
Determine the chemical properties and reactivity of the molecules.
Provide energy for cellular respiration.
Store genetic information directly.
Form the primary structure of proteins.
Life is composed of _______.
matter
energy
light
sound
Which of the following are properties of matter?
Occupies space
Has mass
Both A and B
None of the above
Elements are unique forms of matter with specific _______ and _______ properties.
chemical; physical
atomic; molecular
solid; liquid
mass; volume
What do the silver rods in the molecular model indicate?
chemical bonds
electrons
protons
atomic nuclei
Which of the following statements is true about elements?
Elements can be broken down into smaller substances
Elements cannot be broken down into smaller substances
Elements are always made of three or more letters
Elements are only found in living organisms
What is the chemical symbol for Sulfur?
S
Su
Sf
Sl
What is the chemical symbol for Calcium?
A) Ca
B) C
C) Cl
D) Cm
List the four most common elements of living organisms and their chemical symbols.
Carbon = C, Oxygen = O, Hydrogen = H, Nitrogen = N
Sodium = Na, Potassium = K, Calcium = Ca, Chlorine = Cl
Iron = Fe, Magnesium = Mg, Phosphorus = P, Sulfur = S
Helium = He, Neon = Ne, Argon = Ar, Krypton = Kr
According to the table, what percentage of the human body is made up of Oxygen (O)?
65%
25%
10%
45%
According to the table, which element is most abundant in the atmosphere?
Oxygen
Carbon
Hydrogen
Nitrogen
Carbon is present in the Earth's crust in trace amounts according to the table.
True
False
Match the element to its percentage in the human body according to the table:
Oxygen
65%
Carbon
18%
Hydrogen
10%
Nitrogen
3%
What is the smallest unit of matter that retains all chemical properties of an element?
Atom
Molecule
Proton
Electron
Atoms contain two regions. What is the center of the atom called, and what does it contain?
Nucleus; it contains protons and neutrons.
Electron cloud; it contains electrons and protons.
Core; it contains only electrons.
Shell; it contains neutrons and electrons.
Which region of the atom holds electrons in orbit around the nucleus?
Outermost Region
Nucleus
Proton Region
Neutron Zone
Protons, neutrons, and electrons are referred to as what type of particles?
Sub-atomic particles
Molecular particles
Atomic nuclei
Ionic compounds
Which particles are found in the nucleus of an atom?
Protons and neutrons
Electrons and protons
Electrons and neutrons
Only electrons
Electrons are located in the nucleus of an atom.
True
False
What is the charge of a proton?
+1
0
-1
+2
Which sub-atomic particle is located in the orbitals?
Proton
Neutron
Electron
All of the above
Fill in the blank: Neutrons have a ______ charge and are located in the nucleus.
neutral
positive
negative
double
Match the sub-atomic particle to its correct mass (amu):
Proton
1
Neutron
1
Electron
0
Electrons are considered to have little to no mass.
True
False
Where are protons and neutrons located in an atom?
In the nucleus
In the electron cloud
In the outer shell
In the valence band
Which sub-atomic particle is negatively charged?
Electron
Proton
Neutron
Positron
What is the atomic number of an element?
The atomic number is the number of protons in an element.
The atomic number is the number of neutrons in an element.
The atomic number is the number of electrons in an element.
The atomic number is the sum of protons and neutrons in an element.
Each element has a distinct ________.
atomic number
mass number
melting point
density
What is atomic mass?
Atomic mass is the mass of the atom, roughly equal to the number of protons and neutrons.
Atomic mass is the number of electrons in an atom.
Atomic mass is the total number of atoms in a molecule.
Atomic mass is the energy required to remove an electron from an atom.
True or False: The number of neutrons can vary in an element.
True
False
Elements with different numbers of neutrons are called ________.
isotopes
ions
molecules
allotropes
Do electrons need to be included in the calculation of atomic mass?
True
False
Atomic mass is expressed in ________.
atomic mass units (amu)
grams (g)
liters (L)
moles (mol)
How can we calculate the number of neutrons in an element?
By subtracting the atomic number from the atomic mass.
By adding the atomic number and atomic mass.
By dividing the atomic mass by the atomic number.
By multiplying the atomic number by the atomic mass.
How many neutrons do carbon-12 and carbon-13 have, respectively?
Carbon-12 has 6 neutrons and carbon-13 has 7 neutrons.
Carbon-12 has 7 neutrons and carbon-13 has 6 neutrons.
Carbon-12 has 12 neutrons and carbon-13 has 13 neutrons.
Carbon-12 has 5 neutrons and carbon-13 has 6 neutrons.
The atomic number is the number of protons in an atom, and atomic mass is the total number of protons and neutrons in an atom.
The atomic number is the number of protons in an atom, and atomic mass is the total number of protons and neutrons in an atom.
The atomic number is the number of neutrons in an atom, and atomic mass is the number of electrons.
The atomic number is the sum of protons and electrons, and atomic mass is the number of protons.
The atomic number is the number of electrons, and atomic mass is the number of neutrons.
Select the correct number of neutrons in Au (gold).
118
79
126
92
3. The reason we don’t include electrons when calculating atomic mass is:
Electrons have negligible mass compared to protons and neutrons.
Electrons are heavier than protons and neutrons.
Electrons determine the atomic number, not the mass.
Electrons are not present in atoms.
What is the definition of isotopes?
Forms of an element with different numbers of neutrons, and thus different mass numbers.
Atoms with the same number of protons and neutrons.
Elements that have the same mass number but different atomic numbers.
Molecules with different numbers of electrons but the same atomic number.
How many neutrons does Protium (¹H) have?
0
1
2
3
How many neutrons does Deuterium (²H) have?
1
0
2
3
How many neutrons does Tritium (³H) have?
2
1
0
3
What are radioisotopes?
Isotopes that emit neutrons, protons, and electrons
Isotopes that do not emit particles
Isotopes that only emit electrons
Isotopes that only emit protons
Radiometric dating takes advantage of which natural phenomenon?
The emission of neutrons, protons, and electrons by radioisotopes
The absorption of sunlight by rocks
The movement of tectonic plates
The freezing and thawing of water in rocks
Over time, Carbon-14 decays to which element?
Oxygen-16
Nitrogen-14
Hydrogen-1
Helium-4
Carbon dating can determine the age of remains under ______ years, like this pygmy mammoth.
50,000
5,000
500,000
500
For older objects, scientists use uranium, potassium, or rubidium isotopes.
True
False
Carbon-14 is useful for dating fossils up to ~50,000 years old, but not for million-year-old fossils, because:
After millions of years, almost all C-14 has decayed, making it undetectable.
C-14 increases in concentration over time, making old fossils easier to date.
C-14 is only found in fossils younger than 50,000 years.
C-14 decays too slowly to be useful for dating ancient fossils.
According to the periodic table, what is the atomic number of Hydrogen (H)?
1
2
8
10
According to the periodic table, what is the atomic mass of Helium (He)?
4.003
1.008
12.011
15.999
Which of the following is the symbol for Sodium?
S
Na
So
Sd
Match the element to its symbol:
O
C
N
A
C
B
According to the periodic table, the atomic number appears above the symbol for the element and the approximate atomic mass appears below it.
True
False
According to the Bohr model, what is the relationship between the number of protons and the number of electrons in an atom with a neutral charge?
Number of protons is greater than number of electrons
Number of protons is less than number of electrons
Number of protons equals number of electrons
Number of protons is unrelated to number of electrons
Fill in the blank: The number of electrons in a neutral atom is equal to its _________.
atomic number
mass number
atomic mass
neutron number
Which model describes electrons in circular orbits at specific distances from the nucleus?
Rutherford model
Bohr model
Quantum model
Dalton model
In the Bohr model, what are the electron orbits also called?
Atomic masses
Electron shells or energy levels
Protons
Neutrons
True or False: An electron normally exists in the highest available energy shell.
True
False
Fill in the blank: Electrons fill orbitals closest to the ________ first, then those further away in order.
nucleus
electron cloud
valence shell
proton
Refer to the diagram of the hydrogen atom. Which shell is filled first by an electron?
3n
2n
1n
4n
What is the outer shell of an atom called?
Core shell
Valence shell
Inner shell
Principal shell
The most stable configuration occurs when the _______ is filled.
valence shell
nucleus
inner core
proton shell
According to the diagram, which group of elements has a full valence shell?
Group 1
Group 14
Group 17
Group 18
When the first two outer shells are filled, each will have how many electrons?
Eight electrons
Ten electrons
Six electrons
Twelve electrons
Group 1 elements (H, Li, Na) could achieve stability by _______ an outer electron.
losing
gaining
sharing
splitting
Group 17 elements could achieve stability by gaining one additional electron.
True
False
According to the diagram, which element in Group 1 has two electron shells?
A) H
B) Li
C) Na
Bohr models are incomplete.
True
False
Electrons are in planet-like orbits.
True
False
What are electron orbitals?
Simple circles around the nucleus
Complex shapes that describe how electrons are spatially distributed around the nucleus
Points where electrons are always found
None of the above
Quantum mechanics allows us to ______ where an electron might be at any given time.
predict
ignore
control
eliminate
This predicted area where an electron might be found is known as the ______.
orbital
nucleus
proton
isotope
Refer to the diagram. Which subshell is shaped like a sphere?
1ns subshell
2ns subshell
2np subshell
Both A and B
Within each Bohr model shell are subshells.
True
False
Each subshell (s, p, d, f) has a specified number of orbitals containing electrons.
True
False
The s subshell is (a) and has one orbital.
dumbbell shaped
spherical
cubic
planar
The p subshell is dumbbell shaped and has how many orbitals?
three
one
two
four
Which subshell is labeled as spherical in shape?
1ns subshell
2ns subshell
2np subshell
Both A and B
What are reactants? Fill in the blank: Reactants are substances used at the _______ of a reaction.
beginning
end
middle
peak
What are products? Fill in the blank: Products are substances formed at the _______ of the reaction.
end
start
middle
surface
In the chemical reaction 2H2O2 → 2H2O + O2, which of the following are the reactants?
A) 2H2O2
B) 2H2O
C) O2
D) 2H2O + O2
Fill in the blank: An irreversible reaction proceeds in one direction until all the reactants are used up. For example: 2H₂O₂ → 2H₂O + O₂. The type of reaction shown is _________.
irreversible
reversible
endothermic
exothermic
Fill in the blank: A reversible reaction is when reactants are converted to products but some product can be converted back to reactant. For example: HCO₃⁻ + H → H₂CO₃. The type of reaction shown is _________
reversible
irreversible
combustion
decomposition
Fill in the blank: A ________ is the attractive force that links atoms together to form molecules.
chemical bond
ionic current
magnetic field
thermal energy
What is an ion?
An atom or molecule that has gained or lost one or more protons
An atom or molecule that has gained or lost one or more electrons
An atom or molecule that has gained or lost one or more neutrons
An atom or molecule that has gained or lost one or more nuclei
Fill in the blank: A cation is an ion that ______ electrons.
loses
gains
shares
attracts
Fill in the blank: An anion is an ion that ______ electrons. (e.g., Cl⁻)
gains
loses
shares
removes
Which of the following best describes an ionic bond?
Atoms share electrons equally
Atoms give up or gain electrons
Atoms share protons
Atoms share neutrons
Ionic bonds are formed by the attraction between oppositely charged ions.
True
False
One biological role of ions mentioned in the content is:
Maintaining nerve impulses
Producing light energy
Digesting cellulose
Synthesizing DNA
In the formation of NaCl, which atom loses electrons and which atom gains electrons?
Sodium loses electrons and chlorine gains electrons.
Chlorine loses electrons and sodium gains electrons.
Both sodium and chlorine lose electrons.
Both sodium and chlorine gain electrons.
