Elements
Atoms
Parts of an Atom
Atomic Facts
Periodic Table
100
Substance that can not be broken down into a simpler substance.
Element
100
Smallest part of an element that can still be identified as an element.
Atom
100
Positively charged subatomic particle found in the nucleus.
Proton
100
Number that is unique to each element
Atomic number
100
Swedish scientist who gave us the system of chemical symbols.
Jons Jacob Berzelius
200
Number of natural elements
Ninety-two (92)
200
Greek scientist who thought all matter was made of fire, earth, air and water.
Aristotle
200
Neutral subatomic particle which is part of an atom's mass.
Neutron
200
Mass number minus atomic number gives you the number of this subatomic particle.
Neutrons
200
Russian scientist who arranged the 60+ elements known in the late 1800s by increasing atomic mass.
Dmitri Mendelev
300
Most elements are this type of matter.
Solid
300
English scientist/teacher who thought elements were made of solid spheres.
John Dalton
300
Location of electrons according to the current model of atomic structure.
Electron cloud
300
Atoms are neutral because the number of these two subatomic particles is the same.
Protons and electrons.
300
Columns in the Periodic Table are called this.
Groups or families
400
All matter is made of these.
Atoms
400
Greek philosopher who thought that elements were made of tiny, indivisible particles.
Democritus
400
Scientist who discovered that atoms had a positively charged nucleus.
Ernest Rutherford
400
Total mass of protons and neutrons in an atom; measured in atomic mass units.
Atomic mass
400
Rows in the Periodic Table are called this.
Periods
500
Researched radioactive elements with her husband in the early 1900s.
Marie Curie
500
Device used by scientists to study how atoms are held together.
Particle accelerator
500
Scientist whose model had electrons orbiting the nucleus like planets orbit a sun.
Niels Bohr
500
Number of protons and neutrons in an atom.
Mass number
500
Repeating pattern, or how the Periodic Table got its name.
Periodic
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