WorksheetsLE Unit 2 Study Guide: Atoms to Molecules
Total questions: 50
Worksheet time: 25mins
What does the atomic number of an element represent?
Number of electrons
Number of neutrons
Number of protons
Total number of nucleons
What happens when the number of protons in an atom changes?
It becomes an isotope
It becomes a different element
It gains or loses an electron
It remains the same element
What are isotopes?
Atoms with different numbers of protons
Atoms with different numbers of neutrons
Atoms with different numbers of electrons
Atoms that are ions
An atom that loses an electron becomes a:
Neutral atom
Positively charged ion
Negatively charged ion
Molecule
The outermost electrons in an atom determine its:
Atomic mass
Atomic number
Chemical properties
Isotope form
Changing the number of which particle would change an atom into an ion?
Proton
Neutron
Electron
Nucleon
Which subatomic particle has a neutral charge?
Proton
Neutron
Electron
Ion
What is the significance of valence electrons in chemical reactions?
They determine how atoms bond with each other
They determine the atomic mass
They are only present in metals
They are the same as free radicals
In the atomic nucleus, you would find:
Electrons and protons
Protons and ions
Protons and neutrons
Neutrons and electrons
A neutral atom has the same number of:
Protons and neutrons
Protons and electrons
Electrons and neutrons
Isotopes and ions
What type of bond is primarily responsible for water's unique properties?
Ionic bond
Hydrogen bond
Covalent bond
Metallic bond
Water's ability to stick to other substances is known as:
Cohesion
Adhesion
Osmosis
Hydrophobic interaction
Which property allows water to absorb a lot of heat without a significant increase in temperature?
Polarity
High specific heat capacity
Low boiling point
High surface tension
Why is water considered a universal solvent?
Because it dissolves many substances due to its polarity
Because it is abundant
Because it is a liquid at room temperature
Because it can freeze and melt easily
As ice, water is
more
less
equally
unpredictably
What causes water to have surface tension?
Cohesion of water molecules
Adhesion to surfaces
Its high boiling point
The presence of salts
In a water molecule, the oxygen atom is:
Partially negative charged
Partially positive charged
Completely negative charged
Completely positive charged
Capillary action in plants is primarily due to water's:
Boiling point
Adhesion and cohesion properties
Freezing point
Solvent properties
Water's ability to form hydrogen bonds contributes to its:
Low specific heat
Solubility in oil
High heat of vaporization
Conductivity
The pH of pure water is:
15
6
7
8
Ionic bonds are formed through the:
Sharing of electrons
Transfer of electrons
Sharing of protons
Transfer of neutrons
Covalent bonds are characterized by:
Transfer of electrons between atoms
Sharing of electrons between atoms
Sharing of protons between atoms
Transfer of ions between atoms
In a polar covalent bond, electrons are:
Shared equally between atoms
Shared unequally between atoms
Not shared
Completely transferred
Hydrogen bonds are:
Weaker than covalent bonds but important in biological systems
Stronger than ionic bonds
Only found in water molecules
The main bond in ionic compounds
What type of bond holds the atoms in a water molecule together?
Ionic bond
Polar covalent bond
Hydrogen bond
Metallic bond
A single covalent bond involves the sharing of:
One electron
Two electrons
Three electrons
Four electrons
What happens in an ionic bond when an atom loses an electron?
It becomes a negative ion
It becomes a positive ion
It remains neutral
It becomes a molecule
Which bond is most common in organic molecules?
Ionic bond
Covalent bond
Hydrogen bond
Metallic bond
A molecule with a partial positive charge and a partial negative charge is a result of:
Polar covalent bonding
Nonpolar covalent bonding
Ionic bonding
Metallic bonding
Hydrogen bonds can form between:
Any types of atoms
Only hydrogen atoms
Molecules with polar covalent bonds
Metals and nonmetals
An acid is a substance that:
Releases hydrogen ions (H+) in solution
Releases hydroxide ions (OH-) in solution
Absorbs hydrogen ions (H+) in solution
Absorbs hydroxide ions (OH-) in solution
A solution with a pH of 8 is:
Neutral
Strongly acidic
Strongly basic
Weakly basic
Bases typically:
Taste sour
Feel slippery
React with metals
Turn litmus paper red
The pH scale measures:
The concentration of hydroxide ions
The concentration of hydrogen ions
The temperature of a solution
The solubility of a substance
A substance with a pH lower than 7 is:
Acidic
Basic
Neutral
Alkaline
Which property is common to acids?
Slippery feel
Turn blue litmus paper red
Bitter taste
Solid at room temperature
Buffers are important in biological systems because they:
Increase pH changes
Resist changes in pH
Neutralize all acids and bases
Convert acids to bases
If a substance has a pH of 5, it has times more hydrogen ions than a substance with a pH of 6.
2
5
10
100
A neutral solution has a pH of approximately:
5
6
7
8
In the human body, blood pH is maintained around a value of:
5.5
6.5
7.4
8.4
Which of the following is not a macromolecule?
Carbohydrates
Proteins
Water
Nucleic Acids
Carbohydrates are primarily used in the body for:
Energy
Insulation
Speeding up chemical reactions
Storing genetic information
Lipids are:
Soluble in water
Made of amino acids
Important for energy storage and insulation
The main source of energy in the body
Proteins are polymers made of:
Nucleotides
Fatty acids
Monosaccharides
Amino acids
DNA and RNA are types of:
Carbohydrates
Lipids
Nucleic acids
Proteins
The monomers of carbohydrates are:
Fatty acids
Amino acids
Simple sugars
Nucleotides
Saturated fats have bonds between carbon atoms.
Single
Double
Triple
No
Enzymes, which speed up biochemical reactions, are:
Lipids
Nucleic acids
Proteins
Carbohydrates
Which macromolecule is the main component cell membranes?
Carbohydrates
Proteins
Lipids
Nucleic acids
RNA's primary function is to:
Store genetic information
Provide energy
Assist in protein synthesis
Form cellular structures
