Module 1: Atomic Theory and Periodicity Flashcards
What is chemistry often referred to as?
The central science.
What is the focus of chemistry?
The study of matter and the changes it undergoes.
What is matter?
Anything that has mass and occupies space.
Name the three main states of matter.
Solids, liquids, gases.
What is atomic theory?
A theory that states matter is composed of discrete units called atoms.
What are the three subatomic particles in an atom?
Protons, neutrons, and electrons.
What defines the atomic number of an element?
The number of protons in its nucleus.
What is the mass number?
The total number of protons and neutrons in an atom’s nucleus.
What is an isotope?
Atoms of the same element with different numbers of neutrons.
What is the periodic table?
A tabular arrangement of the elements based on atomic number, electron configurations, and recurring chemical properties.
What are alkali metals?
Elements in Group 1 of the periodic table.
What are noble gases?
Elements in Group 18 of the periodic table, known for being inert.
What is a chemical bond?
The force that holds atoms together in a molecule or compound.
What is an ion?
An atom or molecule with a net electric charge due to the loss or gain of one or more electrons.
What is an ionic bond?
A type of chemical bond formed between two ions with opposite charges.
- one atom donates electrons
- ex NaCl
What is a covalent bond?
A chemical bond that involves the sharing of electron pairs between atoms.
- ex H2O
What is electronegativity?
The ability of an atom to attract electrons in a chemical bond.
Which element has the highest electronegativity?
Fluorine.
What is a physical change?
A change in the form or appearance of matter, not in its chemical composition.
What is a chemical change?
A change where a new substance is formed with different properties.
Condensation
gas to liquid
deposition
gas to solid
sublimation
solid to gas
vaporization
liquid to gas
Classify matter
Pure substance - element or compound
Mixture - homogenous or heterogenous
What are the 4 concepts in atomic theory?
- Each element is composed of atoms
- All atoms of a given element has the same mass and other properties that distinguish them from atoms of other elements
- Atoms combine in simple, whole-number ratios to form compounds
- Atoms of one element cannot change into atoms of another element. In a chemical reaction, atoms change the way they are bound together with other atoms to form a new substance
Z
Atomic number - protons
A
Mass number - protons+neutrons
Atomic Mass
(amu): the average mass of an element based upon the mass of the isotopes that compose that element, weighted according to the natural abundance of each isotope
Molar Mass
(g/mol): mass of a given element divided by the amount of substance
Which atomic orbitals do we need to know?
s, p, d
Aufbau principle
an electron occupies orbitals in order from lowest energy to highest
Pauli Exclusion Principle
no two electrons can be the same and must, therefore, be spin-paired
Ionic Size
- Cations are smaller than their corresponding atoms
- Anions are larger than their corresponding atoms
