> Explain how different observations and experiments led to changes
in the atomic model.
The atomic model has progressed over time. As scientists have learned
more about the atoms, the atomic model has changed.
Democritus: first proposed that matter cannot be divided into smaller
pieces
Dalton: created the 1st atomic theory. He viewed atoms as
tiny solid balls
JJ Thomson: discovered electrons, he showed that atoms are made of even
smaller things
Rutherford: discovered protons and nucleus, he showed that atoms have
positive particles in the center and that atoms are made up mostly of empty
space
Bohr: improved Rutherford’s model by proposing that electrons move around
the nucleus in layers or shells
Chadwick: discovered neutrons = particles with no charge
The modern model of the atom is made up of works collaborated since 1920
which has electrons moving around the nucleus in a cloud.
> Explain how line spectra are used to identify elements and what they
indicate about atoms.
Actually each element has its own unique spectra,
hence this property can be used to identify the element. The line spectra give
us an indication about the energy levels of the electrons, and each wavelength
produces different colors.
> Represent electron arrangements using electron configuration, orbital
notation, shorthand notation, and Lewis dot notation.
To answer your question, I will illustrate an example. The s orbital can
accommodate 2 electrons, p orbital can accommodate 6, d orbital can accommodate
10, f orbital can accommodate 14. To take as example, Mg contains 12 electrons
using the Aufbau principle, the electron configuration is: 1s2 2s2 2p6 3s2 the numbers
after the letter represent the amount of electrons, the letters (s, p)
represent the sublevel of the electron, while the number before the letter
represent the principal quantum number, or "level".
Apply the rules and limitations of each quantum number to identify possible and
impossible quantum number sets.
>There are four quantum numbers.
1. Principal quantum number (n) can take values of any
positive whole numbers
2. Angular momentum quantum number (l) is from 0 to n – 1
3. Magnetic quantum number (ml) is from –l to +l
4. Spin quantum number (ms) only takes two values,
positive spin and negative spin: +1/2, -1/2
From these rules you can identify possible and impossible
set of quantum numbers.
