Chapter 2: Basic Chemistry

Matter

Anything that occupies spance and has weight

Element

Is matter that composes of atoms that have the same number of positive changes in their nuclei

Atom

Smallest unit of an element with that element’s chemical characteristics

What are the four elements that comprise 96% of body weight?

Oxygen, Carbon, Hydrogen, and Nitrogen

Proton

Positively charged subatomic particle found in the nucleus of an atom

Neutron

Neutral subatomic particle found in the nucleus of an atom

Electrons

Negatively charged subatomic particle the nucleus of an atom

Three types of chemical bonds

Covalent, Hydrogen, and Ionic

Ionic bond

Caused by a transfer of electrons between atoms

Covalent bond

Involving a sharing of electrons by the outer shells of the atoms

Hydrogen bond

An intermolecular attraction, not caused by transfer of electrons or sharing of electrons by outer shells of the atoms

What happens in a ionic bond?

An atom gives away one or more molecules

What happens in covalent bonds?

Two atoms share one or more electrons

What happens in a hydrogen bond?

A relatively weak bond between two oppositely partically charged sides of two or more molecules

Ions

Atoms or groups of atoms that carry an electrical charge

Two types of ions

Cations: Positively charged

Anions: Negatively charged

Electrolyte

Forms ions when dissolved in water

physical change

Reducing or gaining

Chemical change

Adding something that changes the state of the initial substances

Atomic number

The number of protons in the nucleus

Atomic mass

Sum of the numbers of protons and neutrons in the nucleus of the atom

Isotope

A different form of the same atom; same atomic number, different atomic mass

Electron shells

Electrons surrounding nucleus in orbits

Each shells can hold electrons

First shell: 2 electrons

Second and third shells: 8 electrons each

Molecules

Two or more atoms bonded together

Compound molecules

Formed by two or more different atoms

Chemical reaction

The interaction of atoms of molecules or compounds to form new chemical combinations

Catalysts

Chemical substances that speed up the rate of chemical reaction

Enzymes

Proteins that serve as catalysts

Acid

An electrolyte that dissociates into hydrogen ion (H+) and an ion

Base

Substance, often hydrogen