Year 11 Chemistry - Term 1 PowerPoint Study Notes

Atom Structure:
- Atoms can be modeled as a nucleus surrounded by electrons in distinct energy levels.
Terminology:
- Distinguish between atomic number (Z), mass number (A), and isotopes of an element.
Nuclear Symbol Notation:
- Apply notation to calculate the number of protons, neutrons, and electrons in atoms, ions, and isotopes.
Isotopes:
- Isotopes are atoms of the same element that differ in neutron counts.
- Representation: Can be expressed in IUPAC notation or as X-A.

Key Questions:
1. Name the three main subatomic particles that compose atoms and their charges.
2. Identify which particles exist in a cloud surrounding the nucleus.
3. In a neutral atom, the number of equals the number of ___; this corresponds to the atomic number.
4. To find the number of neutrons in a neutral atom using the mass number:
- Formula: Mass number - Atomic number.
1. Identify the element with 12 protons.
2. Define ‘ion’ and categorize ions as positive (cations) or negative (anions).
3. Calculate the protons and electrons in O²⁻ and Na⁺.
4. Define ‘isotope’ and provide information for Carbon-12 and Carbon-13.

Protons (positive), neutrons (neutral), electrons (negative).
Electrons.
Protons, electrons.
Mass number - atomic number.
Magnesium.
An atom with an imbalance of electrons and protons. Cations = positive ions, Anions = negative ions.
O²⁻: Protons = 8, Electrons = 10; Na⁺: Protons = 11, Electrons = 10.
Carbon-12: 6 protons, 6 electrons, 6 neutrons. Carbon-13: 6 protons, 6 electrons, 7 neutrons.

Neutral Atoms: Same number of protons and electrons.
Ions: Charged species where number of protons does not equal number of electrons.
- Cations: Fewer electrons than protons (positive charge).
- Anions: More electrons than protons (negative charge).
Isotopes: Same number of protons and electrons, but differing neutrons, also differing mass numbers.

All atoms of the same element possess the same number of protons.
Mass Number (A): Varies based on the number of neutrons in the atom.
EXAMPLE: Hydrogen has three isotopes.
Notation: Isotopes can be expressed in two forms.

Calculate Subatomic Particles for given isotopic symbols:
- _{13}^{27}Li, \, _{18}^{40}O, \, _{92}^{238}U

Isotope Properties: Same electron configuration, similar chemical properties, distinct physical properties.
Relative Atomic Mass: Definition and calculation.
Mass Spectrometry: Operational understanding and its implications in determining isotopic composition and relative atomic mass.

The ionization of substances leads to spectral output that indicates isotopic composition and relative atomic masses.
Each atom's mass is expressed relative to the standard of 1/12 the mass of a carbon-12 atom.

Provide insights about the relative abundances of isotopes and mass compositions throughout the periodic table.

Chromatography:
- Techniques for component separation based on interactions with a stationary phase and a mobile phase.
- Retention factor (Rf) calculations as a measure of travel distances.

Atomic Absorption Spectroscopy (AAS): Measures light absorption to determine metal concentrations in samples via calibration curves.

Across a Period: Increasing atomic number influences element behaviors, including charge and reactivity.
Main Groups of Elements: Discuss varying properties from alkali to noble gases.
Valence Electrons: Key role in chemical reactions; define elemental behavior in terms of electrical formations.

Employ VSEPR Theory to ascertain shapes and angles in various molecular structures.

The chemistry essentials built upon atomic and electron theory lay groundwork for understanding compound formations, reactivity and exploratory techniques for analyzing materials.