1. Atomic Structure & the Periodic Table Flashcards
What are the three states of matter, and how can they be interconverted?
Solid, liquid, and gas.
Interconversions occur through processes such as:
melting (solid to liquid)
freezing (liquid to solid)
vaporization (liquid to gas), condensation (gas to liquid)
sublimation (solid to gas)
deposition (gas to solid).
Define an element and describe its representation in the periodic table.
An element consists of only one type of atom.
Elements are represented by chemical symbols in the periodic table, where each symbol corresponds to a specific element.
For example, O represents oxygen.
Describe the structure of an atom according to the modern atomic model.
Atoms consist of a central nucleus composed of protons (positively charged) and neutrons (neutral), surrounded by electrons (negatively charged) orbiting in energy levels or shells.
The number of protons defines the atomic number, while the sum of protons and neutrons gives the mass number.
What is the relationship between the number of protons, electrons, and the overall electrical charge of an atom?
In an atom, the number of electrons equals the number of protons, resulting in no overall electrical charge.
Define isotopes.
Isotopes are atoms of the same element with different numbers of neutrons, but the same number of protons.
For instance, carbon-12 and carbon-14 are isotopes of carbon.
How are atoms represented using atomic notation?
Atoms are represented by showing their mass number (sum of protons and neutrons) and atomic number (number of protons).
For example, sodium with a mass number of 23 and atomic number 11 is represented as 23 Na 11
Explain the concept of electron energy levels or shells within an atom.
Electrons occupy specific energy levels or shells within an atom. They fill the lowest available energy levels first, following the Aufbau principle.
First shell holds 2 electrons, rest hold 8.
What are the relative masses of protons, neutrons, and electrons?
Protons and neutrons have a relative mass of 1, while electrons have a very small mass compared to protons and neutrons.
Define relative atomic mass (Ar)
It is an average value for the isotopes of the element, reflecting the abundance of each isotope.
How is the periodic table arranged, and why is it called “periodic”?
The periodic table is arranged in order of atomic (proton) number. Elements with similar properties are grouped into columns called groups. It is called “periodic” because similar properties recur at regular intervals.
What defines elements in the same group of the periodic table, and how does it affect their chemical properties?
Elements in the same group have the same number of electrons in their outer energy level, leading to similar chemical properties.
Explain the significance of Group 0 in the periodic table.
Group 0 elements, known as noble gases, have stable electron arrangements, making them unreactive. They have full outer energy levels, with helium having two electrons and other noble gases having eight electrons.
