Atomic structure Flashcards
What are atoms?
Atoms are the smallest part of an element that can exist.
How are atoms represented?
Atoms are represented by chemical symbols, which always start with a capital letter.
Examples: Oxygen (O), Helium (He)
What is the approximate radius of an atom?
The atomic radius is approximately $1 \times 10^{-10}$ m.
What is the radius of an atomic nucleus?
The nucleus radius is less than $1 \times 10^{-4}$ m.
What is an element?
An element is a substance composed of only one type of atom.
How many unique elements are there?
There are over 100 unique elements.
What is a compound?
A compound is a substance containing two or more different elements chemically combined in fixed proportions.
What are the key properties of compounds?
Compounds are different from their constituent elements and can only be separated through chemical reactions.
Give an example of a compound.
An example of a compound is iron oxide, which is a combination of iron and oxygen.
What are subatomic particles?
Subatomic particles include protons, neutrons, and electrons.
What is the charge and location of protons?
Protons have a charge of +1 and are located in the nucleus.
What is the charge and location of neutrons?
Neutrons have a charge of 0 and are located in the nucleus.
What is the charge and relative mass of electrons?
Electrons have a charge of -1 and are located in electron shells with a relative mass of approximately $\frac{1}{2000}$.
What is the maximum capacity of the first electron shell?
The first shell can hold a maximum of 2 electrons.
What is the maximum capacity of the second electron shell?
The second shell can hold a maximum of 8 electrons.
What is the maximum capacity of the third electron shell?
The third shell can hold a maximum of 8 electrons.
What is the electron placement strategy?
Electrons are placed starting with the innermost shell and filling shells sequentially.
Example: Carbon (6 electrons) → 2 in first shell, 4 in second shell.
What are isotopes?
Isotopes are atoms of the same element with the same number of protons but different numbers of neutrons.
Give examples of helium isotopes.
Helium-4 has 2 protons and 2 neutrons, while Helium-3 has 2 protons and 1 neutron.
What are ions?
Ions are charged particles formed when an atom gains or loses electrons.
How is the charge of an ion determined?
Losing electrons results in a positive ion, while gaining electrons results in a negative ion.
Example: Beryllium ion losing 2 electrons becomes 2+ charged.
What is relative atomic mass?
Relative atomic mass is the average mass of an element’s atoms compared to $rac{1}{12}$ of a carbon-12 atom.
How is relative atomic mass calculated?
Relative Atomic Mass = $rac{( ext{Percentage}_1 \times ext{Mass}_1) + ( ext{Percentage}_2 \times ext{Mass}_2)}{100}$.
Why do decimal values exist in atomic mass?
Decimal values exist due to averaging different isotope masses.
What are mixtures?
Mixtures are physical combinations of substances.
What is filtration?
Filtration is a technique to separate insoluble solids from liquids.
What is simple distillation?
Simple distillation is used to separate a solvent from a solution.
What is fractional distillation?
Fractional distillation separates liquids with different boiling points.
What is crystallization?
Crystallization is a technique to separate dissolved solids.
What is chromatography?
Chromatography is used to separate colored compounds.
What was Dalton’s model of the atom?
Dalton’s model depicted the atom as a solid, indivisible sphere.
What was Thompson’s Plum Pudding Model?
Thompson’s model represented the atom as a positive charge with embedded electrons.
What was Rutherford’s Nuclear Model?
Rutherford’s model described a concentrated positive nucleus with mostly empty space.
What is the Electron Shell Model?
The Electron Shell Model describes electrons in fixed shells.
What is the Modern Model of the atom?
The Modern Model includes protons, neutrons, and electrons with a precise understanding of their arrangement.
What does the structure of the periodic table represent?
Columns represent groups, and rows represent periods.
What are group characteristics in the periodic table?
Elements in the same group have the same outer shell electron count.
Example: Group 1 has one outer shell electron.
What are period characteristics in the periodic table?
Elements in the same period have the same number of electron shells.
