Full Notes on Atoms, Molecules, and Ions PDF

\#\#\# Full Notes on Atoms, Molecules, and Ions \-\-- \#\#\# 1. \*\*Atoms\*\* \#\#\#\# \*\*1.1 What is an Atom?\*\* An atom is the smallest unit of an element that retains the properties of that element. Atoms are the building blocks of matter and consist of three primary subatomic particles: \...

\#\#\# Full Notes on Atoms, Molecules, and Ions \-\-- \#\#\# 1. \*\*Atoms\*\* \#\#\#\# \*\*1.1 What is an Atom?\*\* An atom is the smallest unit of an element that retains the properties of that element. Atoms are the building blocks of matter and consist of three primary subatomic particles: \- \*\*Protons\*\*: Positively charged particles found in the nucleus (center) of the atom. \- \*\*Neutrons\*\*: Neutral particles (no charge) that are also found in the nucleus. \- \*\*Electrons\*\*: Negatively charged particles that orbit around the nucleus in regions called electron shells. \#\#\#\# \*\*1.2 Atomic Structure\*\* The structure of an atom can be described in terms of: \- \*\*Nucleus\*\*: Contains protons and neutrons. It has a positive charge due to the protons. \- \*\*Electron Cloud\*\*: Electrons move around the nucleus in specific energy levels (orbitals). These electrons are arranged in shells, with each shell having a specific capacity for electrons. \#\#\#\# \*\*1.3 Atomic Number & Mass Number\*\* \- \*\*Atomic Number (Z)\*\*: The number of protons in an atom\'s nucleus. It defines the element. \- \*\*Mass Number (A)\*\*: The total number of protons and neutrons in an atom. It determines the isotope of an element. \#\#\#\# \*\*1.4 Isotopes\*\* Isotopes are atoms of the same element that have the same number of protons but a different number of neutrons, which results in a different mass number. For example, Carbon-12 and Carbon-14 are isotopes of carbon. \#\#\#\# \*\*1.5 Atomic Theory (Dalton's Atomic Theory)\*\* \- \*\*Each element is made of atoms that are indivisible.\*\* \- \*\*Atoms of the same element are identical in size, mass, and other properties.\*\* \- \*\*Atoms combine in simple whole-number ratios to form compounds.\*\* \- \*\*Atoms are rearranged in chemical reactions, but are not created or destroyed.\*\* \-\-- \#\#\# 2. \*\*Molecules\*\* \#\#\#\# \*\*2.1 What is a Molecule?\*\* A molecule is a group of two or more atoms chemically bonded together. Molecules can consist of the same or different elements. \- \*\*Molecules of an element\*\*: These consist of only one type of atom. Example: O₂ (oxygen molecule). \- \*\*Molecules of a compound\*\*: These consist of atoms of different elements. Example: H₂O (water molecule). \#\#\#\# \*\*2.2 Types of Chemical Bonds\*\* \- \*\*Covalent Bond\*\*: When atoms share electrons to achieve stability. These bonds form molecules. \- Example: In H₂O, the oxygen atom shares electrons with two hydrogen atoms. \- \*\*Ionic Bond\*\*: Occurs when electrons are transferred from one atom to another, leading to the formation of ions that are held together by electrostatic attraction. \- Example: In NaCl (table salt), sodium (Na) transfers an electron to chlorine (Cl), forming Na⁺ and Cl⁻ ions, which attract each other. \#\#\#\# \*\*2.3 Molecular Formula\*\* A molecular formula shows the number and types of atoms in a molecule. \- Example: The molecular formula of water is H₂O (2 hydrogen atoms, 1 oxygen atom). \#\#\#\# \*\*2.4 Chemical Structure\*\* The structure of a molecule refers to how its atoms are connected. It can be represented in several ways: \- \*\*Lewis Structure\*\*: Depicts the bonds between atoms and lone pairs of electrons. \- \*\*Structural Formula\*\*: Shows how atoms are bonded together in space. \- \*\*Ball-and-Stick Model\*\*: A 3D representation of molecules, showing bond angles. \-\-- \#\#\# 3. \*\*Ions\*\* \#\#\#\# \*\*3.1 What is an Ion?\*\* An ion is an atom or a molecule that has a net electrical charge because it has gained or lost one or more electrons. \- \*\*Cations\*\*: Positively charged ions, formed when an atom loses electrons. Example: Na⁺, Ca²⁺. \- \*\*Anions\*\*: Negatively charged ions, formed when an atom gains electrons. Example: Cl⁻, O²⁻. \#\#\#\# \*\*3.2 Formation of Ions\*\* \- \*\*Ionic Bonding\*\*: Involves the transfer of electrons from one atom to another. For example, Na (sodium) loses one electron to form Na⁺, and Cl (chlorine) gains one electron to form Cl⁻, which results in the formation of NaCl (salt). \- \*\*Electrolysis\*\*: The process of using electricity to decompose compounds into ions. Example: Breaking down water (H₂O) into hydrogen (H₂) and oxygen (O₂) gases. \#\#\#\# \*\*3.3 Polyatomic Ions\*\* These are ions composed of two or more atoms covalently bonded but carrying a net charge. Example: \- \*\*Ammonium (NH₄⁺)\*\*: A positively charged polyatomic ion. \- \*\*Sulfate (SO₄²⁻)\*\*: A negatively charged polyatomic ion. \-\-- \#\#\# 4. \*\*Relationship Between Atoms, Molecules, and Ions\*\* \- \*\*Atoms\*\* are the fundamental units of matter. When they bond together, they form \*\*molecules\*\*. \- \*\*Ions\*\* are atoms or molecules that have gained or lost electrons. Ions can form when atoms or molecules undergo ionic bonding or ionization. \- \*\*Molecules\*\* can be neutral or charged. If charged, they are referred to as \*\*polyatomic ions\*\*. \-\-- \#\#\# 5. \*\*Important Concepts\*\* \#\#\#\# \*\*5.1 Law of Conservation of Mass\*\* During a chemical reaction, atoms are neither created nor destroyed. The mass of the products will always equal the mass of the reactants. \#\#\#\# \*\*5.2 Periodic Table and Atomic Structure\*\* The periodic table organizes elements based on their atomic structure. Elements in the same group (column) share similar chemical properties due to having the same number of valence electrons. \- \*\*Metals\*\*: Tend to lose electrons to form cations (positively charged ions). \- \*\*Nonmetals\*\*: Tend to gain electrons to form anions (negatively charged ions). \- \*\*Noble Gases\*\*: Have a full outer electron shell and are typically chemically inert. \-\-- \#\#\# 6. \*\*Summary of Key Differences: Atoms, Molecules, and Ions\*\* \| \*\*Property\*\* \| \*\*Atom\*\* \| \*\*Molecule\*\* \| \*\*Ion\*\* \| \|\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--\|\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--\|\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--\|\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--\| \| \*\*Definition\*\* \| The smallest unit of an element \| Two or more atoms bonded together \| An atom or molecule with a net charge \| \| \*\*Example\*\* \| Hydrogen (H) \| Water (H₂O) \| Sodium ion (Na⁺) \| \| \*\*Charge\*\* \| Neutral \| Neutral (unless a polyatomic ion) \| Charged (either + or -) \| \| \*\*Structure\*\* \| Protons, neutrons, electrons \| Atoms bonded by covalent or ionic bonds \| Atoms or molecules that have gained/lost electrons \| \| \*\*Composition\*\* \| Single element \| Multiple atoms, may be the same or different elements \| Single or multiple atoms, may have a charge \| \-\-- \#\#\# 7. \*\*Debriefing: Reflection and Understanding\*\* 1\. \*\*Atoms\*\* are the building blocks of all matter and consist of protons, neutrons, and electrons. 2\. \*\*Molecules\*\* are formed when atoms bond together either by sharing electrons (covalent bonding) or by transferring electrons (ionic bonding). 3\. \*\*Ions\*\* are charged particles formed when atoms or molecules gain or lose electrons. \-\-- Let me know if you\'d like any part of this expanded or need further clarification!