Introduction to Basic Chemistry, Water, and pH

What is matter composed of?

matter is composed of atoms

What are the three primary subatomic particles that make up an atom?

protons, neutrons, and electrons

What does the atomic number represent in an atom?

represents the number of protons in an atom

What is the difference between mass and weight?

mass refers to the amount of substance, while weight refers to the force gravity exerts on that substance

What is an element?

an element is any substance that cannot be broken down to any other substance by ordinary chemical means

What are isotopes?

isotopes are atoms of a single element that possess different numbers of neutrons

What defines a cation?

a cation is a charged particle with more protons than electrons, resulting in a net positive charge

What defines an anion?

an anion is a charged particle with fewer protons than electrons, resulting in a net negative charge

What is the octet rule?

the octet rule states that atoms tend to establish full outer energy levels

What distinguishes ionic bonds?

ionic bonds are formed by the attraction of oppositely charged ions

How is a covalent bond formed?

a covalent bond is formed when atoms share two or more valence electrons

What is electronegativity?

electronegativity is an atom's affinity for electrons

What happens during oxidation in a redox reaction?

oxidation is the loss of an electron

What happens during reduction in a redox reaction?

reduction is the gain of an electron

What is the significance of hydrogen bonds in water?

hydrogen bonds allow water molecules to stick to one another, contributing to properties like cohesion

What is the pH of pure water?

the pH of pure water is 7, considered neutral

What defines an acid?

an acid is any substance that dissociates in water to increase the hydrogen ion concentration [H+]

What defines a base?

a base is a substance that abosrbs with H+ in water, reducing the hydrogen ion concentration [H+]

What is a buffer?

a buffer is a substance that resists changes in pH by absorbing or releasing hydrogen ions

What is the relationship between the structure and function of an atom?

the structure of an atom, particularly the arrangement of its electrons, influences its chemical behavior

What percentage of human body weight is made up of carbon, hydrogen, oxygen, and nitrogen?

these four elements make up 96.3% of human body weight

What is the primary solvent in biological systems?

water is considered the primary solvent in biological systems

How does water's high specific heat benefit organisms?

water's high specific heat allows it to absorb a large amount of energy before changing temperature, helping to stabilize environments

What causes the aggregation (clumped together) of hydrophobic molecules in water?

water causes hydrophobic molecules to stick together because of its polar nature

What is the role of catalysts in chemical reactions?

catalysts help chemical reactions happen faster without being changed permanently

How do temperature and concentration affect chemical reactions?

both temperature and concentration of reactants and products can affect the rate (how fast/far) a chemical reaction goes

What are polar and nonpolar covalent bonds?

polar covalent bonds involve unequal sharing of electrons, while nonpolar covalent bonds involve equal sharing

What is a chemical reaction?

a chemical reaction happens when bonds are formed or broken, changing reactants into products

What happens to the make-up of atoms during chemical reactions?

atoms move between molecules without changing their quantity and identity

Which elements are crucial for organic molecules?

the primary elements in organic molecules are carbon, hydrogen, oxygen, and nitrogen (CHON)