Honors Chemistry Unit 1 – Atomic Structure Video Study Flashcards

Flashcards created from Page 1-3 notes covering atomic structure, models, spectra, isotopes, orbitals, electron configurations, periodic trends, and periodic table basics.

Which subatomic particles reside in the nucleus and what are their charges?

Protons (positive) and neutrons (no charge) reside in the nucleus.

Where are electrons located in an atom?

In the electron cloud surrounding the nucleus.

In a neutral atom, how do the numbers of protons and electrons compare?

They are equal.

How do the masses of protons, neutrons, and electrons compare?

Protons and neutrons have similar, much larger masses than electrons.

Democritus

Atomos are invisible and uncuttable. Different shapes and sizes. Matter is made of "atomos"

John Dalton

Atoms of the same element are exactly alike and atoms of different elements are different; Father of Modern Chemistry; first to use experiments to prove atoms

JJ Thompson

Thought that atoms are made of positively charged material with negative particles throughout, the plum pudding model, discovered the electron

Ernest Rutherford

Used gold foil experiments and discovered a small nucleus & that most of the atom is made of empty space

Niels Bohr

Electrons must move around the nucleus like the planets move around the sun, put electrons into energy levels

Modern Scientists (Schrödinger & Heisenberg)

Electrons move around in a cloud not in distinct paths

What are isotopes?

Atoms of the same element with different numbers of neutrons (different masses).

How is isotope notation used?

Isotope notation uses mass number as a superscript and atomic number as a subscript to the element symbol.

What are the three subatomic particles and their symbols?

Proton (+), Neutron (0), Electron (-).

Where are electrons located relative to the nucleus?

In the electron cloud surrounding the nucleus.

What determines the atomic mass and the identity of an atom?

Atomic number determines identity; mass is mainly protons plus neutrons.

What does the atomic number specify?

The number of protons; identifies the element.

What is a key limitation of the Bohr model?

Could not explain all atomic behavior; mainly described energy levels.

What does the quantum model use to describe electron location?

Orbitals and probability clouds (electron distributions).

How many electrons can occupy a single orbital?

Two electrons.

Name the three rules that govern electron configurations.

Aufbau principle, Pauli exclusion principle, Hund’s rule.

What is an absorption spectrum?

Dark lines in a spectrum caused by electrons absorbing energy as they move to higher levels.

What is an emission spectrum?

Bright lines corresponding to energies released as electrons drop to lower levels.

What is the relationship between energy and wavelength in emitted light?

Higher energy corresponds to shorter wavelength; lower energy to longer wavelength.

What is the purpose of flame tests in atomic spectroscopy?

Identify elements by characteristic emission colors produced by excited metal ions.

What are isotopes and how do they affect the average atomic mass?

Isotopes have the same number of protons but different neutrons; the average atomic mass is the weighted average of isotopic masses.

Where are metals, nonmetals, and metalloids located on the periodic table?

Metals on the left, nonmetals on the right, metalloids along the staircase between them.

What are the names of the main groups and periods on the periodic table?

Groups include Alkali metals, Alkaline earth metals, Halogens, Noble gases; periods are horizontal rows.

Who is credited with the periodic law and the first periodic table?

Dmitri Mendeleev (1869).

How do you determine the numbers of protons, neutrons, and electrons for an element from a periodic table or isotope notation?

Protons = atomic number; electrons ≈ atomic number for neutral atoms; neutrons = mass number − atomic number.

What are the three forms of electron configuration notation?

Orbital diagram, full electron configuration notation, condensed (orbital) notation.

What is the purpose of significant digits in calculations?

To perform calculations with correct precision and accuracy (significant digits rules apply).

What is atomic radius?

The distance from the nucleus to the outermost electron shell in a neutral atom. Bottom left is biggest

What is Ionization Energy?

The energy required to remove an electron from a gaseous atom or ion. (Higher=more energy required to remove electron) closer to noble gases harder it gets

What is Electronegativity?

The tendency of an atom to attract electrons in a chemical bond. Chlorine is the best

Chadwick

discovered the neutron

Dmitri Mendeleev

Discovered periodic law and developed first Periodic Table in 1869

Aufbau Principle

Electrons fill orbitals starting from the lowest energy level. 

Pauli Principle

Each orbital can hold a maximum of two electrons, and they must have opposite spins. 

Hund's Rule:

Electrons occupy degenerate (equal energy) orbitals singly before pairing up.