Chemistry Chapter on Matter and Acids

Chemistry

• Matter is made up of tiny particles. Particles are always in motion. Particles move faster at higher temperatures. Particles attract each other. Each type of pure substance has its own particular particle type.
• Matter is categorized into pure substances (elements and compounds) or mixtures (heterogeneous or homogeneous).
• Physical properties include clarity, temperature, density, malleability, luster, ductility, color, conductivity, state, hardness, melting/boiling point, taste, odor, solubility, and texture.
• Chemical properties describe how a substance reacts with another substance. Reactions may include those with acids or oxygen, and result in chemical changes or physical changes. Physical changes result in no new substance formation. Chemical changes result in formation of new substance(s).

Gas Tests

• Gases can be identified using unique tests.
• Carbon Dioxide turns limewater cloudy.
• Oxygen relights a glowing splint.
• Hydrogen creates a "pop" sound with a flaming splint.

Atomic Structure

• Atoms have three subatomic particles: protons, electrons, and neutrons.
• Protons are found in the nucleus with a positive charge (+1).
• Electrons orbit the nucleus with a negative charge (-1)
• Neutrons are found in the nucleus with a neutral charge.
• The atomic number (Z) represents the number of protons in an atom, and defines the element.

Mass Number

• The mass number (A) is the sum of protons and neutrons in an atom's nucleus.
• This is most commonly determined by rounding the listed values for each element on the periodic table.

Nuclear Notation

• Shows the atomic number(Z) and mass number (A), as well as the symbol of an element.

Bohr-Rutherford Model of the Atom

• Electrons orbit the nucleus in energy levels.
• The first energy level holds 2 electrons, the second holds 8, and the third can hold up to 18.
• Valence electrons represent electrons in the outer shell. They are involved in chemical reactions. Atoms react to achieve full valence orbitals.

Periodic Table

• Elements arranged by properties.
• Groups are vertical columns and elements in the same group have the same number of valence electrons. This does not apply to transition metals.
• The octet rule states that atoms (except those with low atomic numbers) will strive to have 8 electrons in their valence shell.

Lewis Diagrams

• Diagrams that show element symbols with dots that represent valence electrons. Atoms will achieve full valence orbitals in chemical reactions.

Ionic compounds

• Made up of a metal and a non-metal.
• Metals form positive ions (cations); non-metals form negative ions (anions).
• Ionic compounds can be named using a criss-cross method to determine the chemical formula. A zero-sum rule applies.

Polyatomic Ions

• A polyatomic ion is made of a stable group of more than one atom that acts as a single charged particle (ion).
• Many are anions, but ammonium is a cation.
• Follow the naming rules for other compounds when using polyatomic ions.

Molecular Compounds

• Formed from two non-metals. Non-metals can share valence electrons to achieve full orbitals. These bonded atoms then form molecules.
• Often have lower melting/boiling points than ionic compounds. They are also usually powders or liquids and do not typically conduct electricity.

Diatomic Molecules

• Two atoms of the same element covalently bonded.

Naming Molecular Compounds

• Use a prefix system to indicate the number of each element that constitutes the molecule.

Chemical Reactions

• A process in which one or more substances are changed into different substances.
• Reactants are the starting substances and products are the substances produced.
• A reaction arrow separates the reactants from the products.

Types of Chemical Reactions

• Synthesis
• Decomposition
• Single displacement (element + compound)
• Double displacement (compound + compound)
• Combustion

Balancing Chemical Equations

• Using coefficients to ensure atoms of each element are equal on both sides of the arrow. Subscripts cannot be changed in balancing equations.

Other Topics

• Signs of a chemical change
• Gas tests
• Atomic structure
• Mass number
• Nuclear notation
• Bohr-Rutherford model
• The periodic table
• Lewis diagrams
• Naming ionic, and molecular compounds
• Chemical reactions
• Types of chemical reactions
• Balancing chemical equations
• Combustion and Corrosion (involves oxygen to produce oxide and release energy.)

Biology

• Cells are the basic unit of life. Living things use energy, grow, reproduce, have smaller parts, respond to stimuli, and maintain homeostasis.
• Cells have different types and are composed of various organelles; organelles serve specific functions within the cell.
• The Cell theory proposes that all organisms consist of one or more cells, cells are the fundamental unit of structure and function, existing cells come from pre-existing cells, and the total activity of an organism is based on the totality of its independent cells.
• Cell division by mitosis results in two identical daughter cells. Specialized cells perform distinct functions within multicellular organisms through a process called cellular differentiation. Undifferentiated cells (stem cells) can develop into specialized cells.
• Body organs work together in a specific order (Hierarchy) to form a complex structure. Organs are composed of tissues, and tissues are composed of cells.