Chapter 2

A&P

Distinguish between matter and energy

Matter has mass & volume

(i.e. solids, liquids, gases)

Energy = the ability to cause change without mass or volume

(i.e. light, heat, sound, motion)

Atom

Basic building block of all matter in the universe

Chemical bonding

the physical process that holds atoms or ions together to form stable compounds, molecules, and crystals

Atoms bond to lower their overall energy to achieve high stability

Solutions

Homogeneous (the same throughout).

Particles do not settle

(i.e. Salt water, sugar in water, soda)

Suspension

Heterogeneous

particles settle at the bottom

(i.e. Muddy water, sand in water, fresh orange juice with pulp)

Colliods

Heterogeneous, though they appear uniform.

particles do not settle out over time.

(i.e Milk, fog, mayonnaise)

Chemical Reaction

a process where starting substances called reactants turn into new substances called products by breaking old chemical bonds and forming new ones

• Breaking bonds always takes energy in from the surroundings.

• Forming bonds always gives energy out to the surroundings.

Inorganic Compounds

Substances that typically lack both carbon and hydrogen bond. They are fundamentally essential for all living organisms such as

Water(h2O) the most abundant and important inorganic compound and a universal solvent.

Salts are ionic compounds formed by the reaction of an acid and a base.

Acids and bases help regulate the pH (the relative concentration of hydrogen ions) in body fluids.

Organic compounds

carbon-containing molecules found in all living things—serve primary functions divided across four major groups of macromolecules:

Carbohydrates: Provide quick, accessible cellular energy (via glucose) and structural support (such as cellulose in plant walls)

Lipids (Fats and Oils): Store long-term energy, insulate the body, and form the core structure of cell membranes (via phospholipids and cholesterol)

Proteins: Build and repair tissues, provide structural framework (in hair, nails, and skin), and act as enzymes to speed up chemical reactions.

Nucleic Acids (DNA and RNA): Store, transmit, and express genetic instructions required to build proteins and direct cellular life.

Matter

anything that has mass and takes up space

Atomic Structure

Structure of an Atom

• The Nucleus: The center of the atom contains the protons and neutrons packed tightly together. This core holds almost all of the atom's mass.

• The Electron Cloud: Electrons move around the nucleus in outer paths or clouds because opposite charges attract each other

Atoms have a positively charged nucleus and have three main types of subatomic particles:

• Protons: These have a positive (+) electrical charge.

• Neutrons: These have no electrical charge (they are neutral).

• Electrons: These have a negative (-) electrical charge

Element

a pure substance that cannot be broken down into any simpler substances by normal chemical methods

Each element is made of only one specific kind of atom.

Isotope

a form of a chemical element that has the same number of protons as other atoms of that element but a different number of neutrons

Ion

an atom or a group of atoms that has an electrical charge

2 Types of Ions

• Anion – negatively charged ion

  Cation – positively charged ions

Molecules

Compounds of 2 + different atoms (i.e. water)

How do molecules form?

- Primarily, Covalent and Ionic Bond

- Molecular bonding with Valence electrons