ATOMIC MODEL
He is known as the “Father of the Atomic Theory.”
John Dalton
A pure substance that cannot be broken down into simpler substances by chemical means.
Elements
He arranged the known elements in order of increasing atomic mass and is called the “Father of the Periodic Table.”
Dmitri Mendeleev
The horizontal rows in the periodic table are called what?
Periods
Elements that are shiny, malleable, ductile, and good conductors of heat and electricity.
Metals
In Rutherford’s gold foil experiment, most alpha particles passed through the foil. What did this show about the atom?
That the atom is mostly empty space.
A pure substance made of two or more elements chemically combined in a fixed ratio.
Compounds
Mendeleev left blank spaces in his periodic table. Why?
To predict undiscovered elements.
The vertical columns in the periodic table are called what?
Groups
Elements that are poor conductors of heat and electricity and are often gases or brittle solids.
Which scientist proposed that electrons orbit the nucleus in specific energy levels or shells?
Niels Bohr
Compounds that contain carbon and hydrogen are generally classified as what type of compound?
Organic compounds
This scientist rearranged the periodic table by atomic number instead of atomic mass, leading to the modern periodic law.
Henry Moseley?
The elements in Group 18 are known for being very stable and unreactive. What are they called?
Noble Gasses
Bio Sir Gets Ashley Polly Sabado's Team
Boron Silicon Germanium Arsenic Polonium Antimony Tellurium
This model describes electrons as existing in a cloud rather than fixed orbits.
Quantum Mechanical Model (or Electron Cloud Model)
Compounds like water (H₂O) and sodium chloride (NaCl) are classified as what type of compound?
Inorganic compounds
This law states that the properties of elements are a periodic function of their atomic numbers.
Modern Periodic Law
These elements, located along the “stair-step” line between metals and nonmetals, have properties of both. What are they called?
Metalloids
The elements located in the center block (Groups 3–12) of the periodic table are known as what type of metals?
Transition metals
What discovery led to the modification of Dalton’s theory that atoms are indivisible?
The discovery of subatomic particles (electrons, protons, and neutrons).
Carbonic acid (H₂CO₃) contains both carbon and hydrogen atoms but no C–H bonds determine what type of compound is it.
Inorganic
Before Mendeleev, this scientist tried to organize elements into groups of three called triads based on similar properties.
Johann Döbereiner
The elements in Group 1 are highly reactive metals that form strong bases when combined with water. What are they called?
Alkali Metals
These elements, found in Group 17, are highly reactive nonmetals that form salts when combined with metals.
Halogens