Atomic Structure And The Periodic Table Flashcards
Describe what is meant by atom and molecule.
Atom - An atom is the smallest unit of an element that retains the chemical properties of that element.
Molecule - A molecule is a group of two or more atoms chemically bonded together.
Describe the structure of an atom
Nucleus - found in core
Protons - found in core
Neutrons - found in core
Electrons - found in shells
Describe the development of the atom from the plum pudding to the structure we have today, including the influence of Bohr and Chadwick.
Plum Pudding Model - Proposed by J.J. Thomson, it described the atom as a ball of positive charge with negatively charged electrons embedded in it.
Bohr Model - Niels Bohr proposed that electrons orbit the nucleus in specific energy levels or shells, and can jump between these levels.
Chadwick - James Chadwick discovered the neutron, a particle within the nucleus with no charge, which helped explain the presence of isotopes.
Explain what is meant by the terms atomic number and mass number.
Atomic Number - The number of protons in the nucleus of an atom, which defines the element.
Mass Number - The total number of protons and neutrons in the nucleus of an atom.
Define an isotope
Isotopes are variants of a particular chemical element that have the same number of protons but different numbers of neutrons, resulting in different mass numbers.
Define relative atomic mass (Ar)
The average mass of atoms of an element relative to the mass of an atom of carbon-12
How is the periodic table is arranged
The periodic table is arranged in order of increasing atomic number, from left to right and top to bottom. This arrangement reflects periodic trends in chemical properties.
Describe how Mendeleev developed the periodic table in terms of atomic number and atomic mass.
Dmitri Mendeleev developed the periodic table by arranging elements in order of increasing relative atomic mass and grouping them by similar chemical properties. He left gaps for elements that had not yet been discovered, predicting their properties based on patterns.
Explain what is meant by groups and periods in the periodic table.
Groups - Vertical columns in the periodic table. Elements in the same group have similar chemical properties and the same number of valence electrons.
Periods - Horizontal rows in the periodic table. Elements in the same period have the same number of electron shells.
Use the groups and the periods in the periodic table to deduce the electronic configuration of the first 20 elements.
Using the periodic table, the position of an element can help determine its electronic configuration. For example, the first element (hydrogen) has one electron, while the 20th element (calcium) has an electronic configuration of 2, 8, 8, 2.
Use the periodic table to identify metals and non-metals by their position.
Metals - Generally located on the left and in the center of the periodic table.
Non-metals - Found on the right side of the periodic table.
Describe the electrical conductivity of metals and non-metals.
Metals - Good conductors of electricity due to the free movement of electrons.
Non-metals - Poor conductors of electricity as they lack free electrons.
Describe how metal oxides are basic and non-metal oxides are acidic.
Metal Oxides - Generally basic, reacting with acids to form salts and water.
Non-metal Oxides - Generally acidic, reacting with bases to form salts and water.
Describe how the electronic configuration of a main group element is related to its position in the periodic table.
The group number corresponds to the number of electrons, and the period number indicates the number of electron shells. For example, elements in Group 1 have one electron, while elements in Period 3 have three electron shells.
Explain why elements in the same group in the periodic table have similar chemical properties.
Elements in the same group have similar chemical properties because they have the same number of electrons, which determines their reactivity and bonding behavior.
