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Chapter 14 and 15 Test - The Atom
Chapter 14 and 15 Test - The Atom - Glencoe Science Book Level Blue
27
Science
8th Grade
11/02/2011

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Cards

Term
• John Dalton
Definition
o hard, sphere
o same throughout
o ex. Marble
Term
• William Crookes
Definition
o hard, sphere
o particles
o ex. Chocolate chip cookie
Term
• J.J. Thomson
Definition
o sphere
o particles
o charged particles found inside the atom
o idea – The atom had equal amounts of positively and negatively charged particles so the atom is neutral.
Term
• Ernest Rutherford
Definition
o sphere
o charged particles
o atom is neutral
o discovered nucleus and neutrons
o Electrons randomly scatter around the nucleus
Term
• Neils Bohr
Definition
o Sphere
o Charged particles
o Atom is neutral
o Nucleus
o Neutrons
o Electrons are found on energy levels in the electron cloud
Term
• Protons
Definition
o Located in the nucleus
o Positive charge
Term
• Neutrons
Definition
o Located in the nucleus
o Neutral or No charge
Term
• Electrons
Definition
o Located outside the nucleus
o Negative charge
Term
• Atomic number
Definition
# of protons
Term
• Mass number
Definition
o Number of protons + number of neutrons
Term
• Number of protons
Definition
atomic number
Term
# of electrons
Definition
# of protons
Term
# of neutrons
Definition
Mass number - # of protons
Term
Atoms & Elements
Definition
Cannot be broken down into simpler substances
Term
molecules & Compounds
Definition
Substances with two or more elements
Term
Old Periodic Table
Definition
• Mendeleev
o 1869
o Arranged elements in order of increasing atomic mass
o Discovered a pattern-elements with similar properties fell into groups
o Left 3 gaps for missing elements
o Based on groupings in Periodic Table he predicted properties for missing elements
Term
New Periodic Table
Definition
• Moseley
o 1913
o Arranged elements in order of increasing atomic number
o Improved Mendeleev’s Periodic Table
o After the new arrangement it was clear how many elements were not discovered
Term
Group
Definition
vertical comumns
Term
periods
Definition
horizontal rows
Term
o Group 18
o Rarely combines with other elements because it outer energy level is filled with electrons.
Definition
• Nobel Gases
Term
o Group 17
o “Salt-formers”
o Reactivity decreases as you move down the group
Definition
• Halogens
Term
o Group 1
o Made of silvery solids with low densities.
o Easily reacts with water
o Reactivity increases as you move down the group.
o Examples: lithium batteries
Definition
• Alkali Metals
Term
o Most have high melting points
 Ex. Tungsten
o Groups 3-12
o All elements in this group are synthetic or man-made except 3
Definition
• Transition Metals
Term
o The lanthanides (rare earth elements)
o The actinides – radioactive elements
Definition
• Inner-transition Metals
Term
o Element that has luster, is malleable, is ductile and good conductors of heat and electricity
Definition
• Metals
Term
o Poor conductors of heat and electricity
o Can be a gas or brittle solid
Definition
• Nonmetals
Term
o An element that shares some properties with both metals and nonmetals
o Also known as semi-metals or semi-conductors
Definition
• Metalloids
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