science exam pt.1

Flashcards generated from lecture notes covering key chemistry concepts, terms, and definitions.

Democritus

An ancient Greek philosopher who proposed that matter is composed of small, indivisible particles called atoms.

Law of electrostatic charges

States that opposite charges attract and like charges repel each other.

Ernest Rutherford

A scientist known for discovering the nucleus and formulating the planetary model of the atom.

Neils Bohr

A physicist who developed a model of the atom that describes electrons moving in fixed orbits around the nucleus.

Thomson's model of the atom

Proposed that atoms are composed of electrons scattered within a 'soup' of positive charge.

JJ Thomson

The scientist who discovered the electron and proposed the 'plum pudding' model of the atom.

Atomic number

The number of protons in the nucleus of an atom, which determines the element's identity.

Subatomic particles

Particles that make up an atom, including protons, neutrons, and electrons.

Mass number

The total number of protons and neutrons in an atom's nucleus.

Isotopes

Atoms of the same element that have different numbers of neutrons and different mass numbers.

Halogen family

Group 17 elements in the periodic table, known for their high reactivity.

Element symbols

One or two-letter abbreviations used to denote elements in the periodic table.

Alkaline earth metals

Group 2 elements in the periodic table that are typically less reactive than alkali metals.

Alkali metals

Group 1 elements that are highly reactive and have one electron in their outermost shell.

Classification of elements

Elements can be classified as metals, nonmetals, or metalloids based on their properties.

Periodic table location

Metals are found on the left side, nonmetals on the right, and metalloids along the staircase line.

Group/family

A vertical column in the periodic table that contains elements with similar chemical properties.

Mendeleev's periodic table arrangement

Arranged elements by increasing atomic mass and by similar properties.

Modern periodic table arrangement

Arranged elements by increasing atomic number.

Valence electrons

Electrons in the outermost shell of an atom that determine its chemical behavior.

Atomic radius

The distance from the nucleus to the outermost electron shell, indicating the size of an atom.

Covalent bond

A bond formed by the sharing of electrons between atoms.

Ionic bond

A bond formed through the transfer of electrons from one atom to another, resulting in charged ions.

Metallic bond

A bond found in metals where electrons are shared among a lattice of metal atoms.

Bonds between metal and nonmetal

Typically ionic bonds, where electrons are transferred from metals to nonmetals.

Polar covalent bond

A bond where electrons are shared unequally between two atoms, leading to partial charges.

Polar molecules

Molecules that have a net dipole due to the presence of polar bonds.

Ion

An atom or molecule with a net electrical charge due to the loss or gain of electrons.

Cation

A positively charged ion, formed when an atom loses one or more electrons.

Anion

A negatively charged ion, formed when an atom gains one or more electrons.

Positive ion

An ion with a positive charge, example: Na+ (sodium ion).

Negative ion

An ion with a negative charge, example: Cl- (chloride ion).

Polyatomic ions

Ions that consist of two or more atoms bonded together that carry a charge.

Naming ionic compounds

Typically involves naming the cation first followed by the anion.

Naming covalent compounds

Often uses prefixes to indicate the number of atoms of each element in the compound.

Chemical bond

The lasting attraction between atoms that enables the formation of chemical compounds.

Oxidation state

The charge of an atom in a compound, indicating the total number of electrons that an atom loses, gains, or shares.

Binary compound

A chemical compound that consists of exactly two different elements.