Advanced Atomic Theory
This is the term for atoms of the same element that have the same number of protons but different numbers of neutrons.
What are isotopes?
This is the specific family name for the highly reactive nonmetals found in Group 7A.
What are the halogens?
Moving left to right across a period, the atomic number always increases by this exact increment from one block to the next.
What is one (1)?
This lightweight Group 8A noble gas is lighter than air and glows yellow-orange when an electric current passes through it.
What is Helium?
This number on the periodic table represents the exact number of protons inside an atom's nucleus and acts as the element's unique ID.
What is the atomic number?
Unlike the Bohr model, the modern atomic model describes this region as a visual probability cloud where electrons are most likely to be found.
What is the electron cloud?
Group 2A elements, which are slightly less reactive than alkali metals, are known by this family name.
What are the alkaline earth metals?
This physical property refers to a material's ability to allow heat or electricity to easily flow through it, which silicon only does under certain conditions.
What is conductivity?
This Group 7A halogen is a highly reactive, pale-yellow gas and is the most chemically reactive of all nonmetals.
What is Fluorine?
If you add up the total number of protons and neutrons in a single specific atom, you get this whole number.
What is the mass number?
If an atom has a mass number of 32 and an atomic number of 16, it contains this exact number of neutrons.
What is 16?
Elements in Group 8A are called "noble" gases because they possess this stable number of valence electrons, making them completely unreactive.
What is eight (8)?
As you move down a metallic group on the table, the outer electrons get further from the nucleus, causing the element's chemical reactivity to do this.
What is increase?
This vital transition metal has an atomic number of 26 and carries oxygen through your bloodstream.
What is Iron?
A neutral atom has an atomic number of 17. This is the exact number of electrons traveling around its nucleus.
What is 17?
When an excited electron falls back down to a lower, more stable energy level, it releases energy in this visible form.
What is light (or a photon)?
This is the unique group name given to the large block of metallic elements spanning columns 3 through 12 in the center of the table.
What are the transition metals?
Element 3 (Lithium) has 1 valence electron, and Element 4 (Beryllium) has 2. This is the exact number of valence electrons found in Element 5 (Boron).
What is three (3)?
This alkali metal has an atomic number of 11 and violently reacts with water to form a basic solution.
What is Sodium?
This is the correct three-number electron shell arrangement formula for an atom of Sulfur (atomic number 16).
What is 2, 8, 6?
J.J. Thomson’s "plum pudding" atomic model was widely accepted until Ernest Rutherford discovered this dense, positively charged center of the atom.
What is the nucleus?
Elements are placed into the exact same vertical group or column because they share these identical chemical traits.
What are chemical properties (or valence electron counts)?
While metals are malleable and shiny, nonmetals in the solid state generally possess these two contrasting physical properties.
What are dull and brittle?
This nonmetal gas makes up nearly 78% of Earth's atmosphere, but is not found in a water molecule.
What is Nitrogen?
An element has two natural isotopes: one with a mass of 10 (19.9% abundance) and one with a mass of 11 (80.1% abundance). This is why the atomic mass on the table is listed as 10.81 instead of 10.50.
What is because it is a weighted average that favors the most abundant isotope?