Basic Chemistry
What are the four most common elements in living organisms?
Carbon (C), Hydrogen (H), Oxygen (O), and Nitrogen (N).
How do covalent bonds form?
Covalent bonds form when two atoms share electrons to fill their outer electron shells.
Why is water a polar molecule?
Water is polar because oxygen has a higher electronegativity than hydrogen, creating a partial negative charge on the oxygen and partial positive charges on the hydrogens.
What is an acid?
An acid is a substance that donates protons (H⁺ ions) in a solution, lowering the pH.
What are reactants?
Reactants are the starting substances in a chemical reaction that undergo change to form products.
What is an isotope?
An isotope is an atom of the same element that has the same number of protons but a different number of neutrons.
Describe ionic bonds with an example.
Ionic bonds form when one atom donates an electron to another, creating ions that attract each other. Example: Sodium chloride (NaCl), where sodium (Na) donates an electron to chlorine (Cl).
What property of water helps regulate temperatures in living organisms and great bodies of water?
High heat capacity
What is a base?
A base is a substance that accepts protons (H⁺ ions) or donates hydroxide ions (OH⁻), raising the pH
What are products?
Products are the substances formed as a result of a chemical reaction.
How does the atomic number relate to protons?
The atomic number of an element equals the number of protons in its nucleus.
Which type of bond is responsible for wateer's unique properties?
hydrogen bonds
What is surface tension?
Surface tension is the cohesive force at the surface of a liquid that allows it to resist external force, due to hydrogen bonding betwen water molecules.
If a solution has a pH of 7 is it acidic or basic?
Explain a synthesis reaction.
A synthesis reaction is when two or more reactants combine to form a more complex product. Example: A + B → AB.
What is the role of trace elements?
Trace elements are essential for various biological processes in small amounts, such as iron in oxygen transport and zinc in enzyme function.
What is the difference between inert and reactive atoms?
Inert atoms, like noble gases, have full outer electron shells and do not readily participate in chemical reactions. Reactive atoms, like oxygen or sodium, have incomplete outer shells and readily form chemical bonds to achieve stability.
What is amphipathic?
Amphipathic molecules have both hydrophilic/polar (water-attracting) and hydrophobic/non-polar (water-repelling) parts, like phospholipids in cell membranes.
Define a buffer.
A buffer is a solution that resists changes in pH by absorbing or releasing H⁺ ions.
What is a decomposition reaction?
A decomposition reaction is when a compound breaks down into simpler substances. Example: AB → A + B.
Describe the structure of an atom.
An atom consists of a nucleus containing protons (positively charged) and neutrons (neutral), with electrons (negatively charged) orbiting around the nucleus in energy levels or shells.
What is the difference between polar and nonpolar covalent bonds?
In polar covalent bonds, electrons are shared unequally between atoms, creating a slight charge difference (dipole). In nonpolar covalent bonds, electrons are shared equally between atoms, resulting in no charge separation.
How do cohesion and adhesion differ?
Cohesion refers to the attraction between molecules of the same substance (e.g., water to water), while adhesion refers to the attraction between molecules of different substances (e.g., water to glass).
How does ocean acidification occur?
Ocean acidification occurs when carbon dioxide (CO₂) from the atmosphere dissolves in seawater, forming carbonic acid (H₂CO₃), which lowers the ocean's pH.
What is an inorganic compund?
lack a c-h bond
•Tend to be simpler compounds
•Example: H2O (water), NaCl (sodium chloride), CO2 (carbon dioxide), O2 (oxygen)