Chemistry Review and Organic Molecules

What is Matter?

Matter is anything that has mass and occupies space. It can exist in various states, including solid, liquid, and gas.

What is an Element?

An element is a pure substance that cannot be broken down into simpler substances and is made up of atoms of the same type. Elements are the building blocks of matter and are organized in the periodic table.

What is a Compound?

A compound is a substance formed when two or more elements chemically combine in fixed proportions. Compounds have unique properties distinct from those of their constituent elements.

What are Essential Elements?

Essential elements are elements that are necessary for the survival and proper functioning of living organisms. They include elements such as carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur.

What are Trace Elements?

Trace elements are chemical elements required by living organisms in minute quantities for various physiological functions. Examples include iron, zinc, and copper.

What is an Atom?

An atom is the smallest unit of matter that retains the properties of an element. It consists of a nucleus containing protons and neutrons, surrounded by electrons in orbitals.

What is the Atomic Number?

The atomic number is the number of protons found in the nucleus of an atom, which determines the element's identity and its position on the periodic table.

What is the Mass Number?

The mass number is the total number of protons and neutrons in the nucleus of an atom, reflecting its isotopic identity.

What is Atomic Mass?

Atomic mass is the weighted average mass of an element's isotopes, measured in atomic mass units (amu), reflecting the abundance of each isotope.

What are Isotopes?

Isotopes are variants of a chemical element that have the same number of protons but different numbers of neutrons, resulting in different mass numbers.

What are Radioactive Isotopes?

Radioactive isotopes are isotopes that are unstable and decay over time, emitting radiation in the process. They have the same number of protons but different neutron counts, leading to different decay rates.

What is the Chemical Activity of Atoms?

The chemical activity of atoms refers to their ability to undergo chemical reactions, which is influenced by the arrangement of electrons in the outer shell. Atoms with unfilled outer electron shells tend to react to achieve stability.

What is a Valence Shell?

The valence shell is the outermost shell of an atom that contains the highest energy electrons. It plays a crucial role in determining how an atom interacts and bonds with other atoms.

What are Valence Electrons?

Valence electrons are the electrons located in the outermost shell of an atom. They are responsible for an atom's chemical properties and bonding behavior.

What are Covalent Bonds?

Covalent bonds are chemical bonds formed when two atoms share one or more pairs of valence electrons. This type of bonding occurs primarily between non-metal atoms, leading to the formation of molecules.

What is a Molecule?

A molecule is a group of two or more atoms bonded together by covalent bonds, representing the smallest fundamental unit of a chemical compound.

What is Electronegativity?

Electronegativity is the measure of an atom's ability to attract and hold onto electrons when forming chemical bonds. It plays a crucial role in determining the nature of bonds between atoms.

What are Non-polar Covalent Bonds?

Non-polar covalent bonds are chemical bonds in which electrons are shared equally between two atoms, typically occurring between identical non-metal atoms or atoms with similar electronegativities.

What are Polar Covalent Bonds?

Polar covalent bonds are chemical bonds in which electrons are shared unequally between two atoms, resulting in a partial positive charge on one atom and a partial negative charge on another, usually occurring between atoms with different electronegativities.

What are Ionic Bonds?

Ionic bonds are chemical bonds that result from the transfer of electrons from one atom to another, leading to the formation of charged ions that are held together by electrostatic forces. They typically occur between metals and non-metals with significantly different electronegativities.

What is an Ion?

An ion is an atom or molecule that has a net electrical charge due to the loss or gain of one or more electrons, resulting in positively charged cations or negatively charged anions.

What is a Cation?

A cation is a positively charged ion that forms when an atom loses one or more electrons. Cations typically result from metal atoms or from ammonium ions.

What is an Anion?

An anion is a negatively charged ion that forms when an atom gains one or more electrons. Anions commonly result from non-metal atoms.

What is Salt?

Salt is an ionic compound formed when a cation bonds with an anion, typically resulting from the reaction between an acid and a base.

What are Hydrogen Bonds?

Hydrogen bonds are weak attractions that occur between a hydrogen atom covalently bonded to an electronegative atom and another electronegative atom.

What is a Chemical Reaction?

A chemical reaction is a process that involves the rearrangement of atoms to transform reactants into products, characterized by changes in energy and the formation or breaking of chemical bonds.

What are the Emergent Properties of Water?

Cohesive behaviour, Ability to moderate temperature, Expansion upon freezing, and Versatility as a solvent.

What is a Hydrophilic Substance?

A hydrophilic substance is one that has an affinity for water, meaning it can interact or dissolve in water due to its polar or ionic nature.

What is a Hydrophobic Substance?

A hydrophobic substance is one that repels water and does not easily dissolve in it, typically due to its nonpolar nature.

What is an Acid?

An acid is a substance that donates protons (H+) in a solution, resulting in an increase in hydrogen ion concentration. Acids typically have a sour taste and can react with bases to form salts.

What is a Base?

A base is a substance that accepts protons (H+) in a solution, leading to a decrease in hydrogen ion concentration. Bases typically have a bitter taste and can react with acids to neutralize them.

What is a Buffer?

A buffer is a solution that resists changes in pH when small amounts of an acid or base are added. It typically contains a weak acid and its conjugate base, helping to maintain a stable pH in biological systems.

What is an Organic Compound?

An organic compound is any chemical compound that contains carbon and is typically found in living organisms. These compounds often include functional groups that determine their chemical properties and reactions.

What are Hydrocarbons?

Hydrocarbons are organic compounds composed entirely of hydrogen and carbon atoms. They serve as the foundational structures for more complex organic molecules.

What is a Carbon Skeleton?

A carbon skeleton is the chain of carbon atoms that forms the backbone of an organic molecule. It can be linear, branched, or ring-shaped, and serves as the framework to which functional groups are attached.

What are Isomers?

Isomers are compounds that have the same molecular formula but differ in the arrangement of atoms or the spatial orientation of their structure, leading to different properties.

What are Chemical Groups?

Atoms that are attached to the carbon skeleton. They influence the properties and reactivity of organic molecules.