Research
Periodic Table
Atomic structure
Atomic properties
Vocabulary
100
In 1911, Ernest Rutherford proposed that atoms had a dense, positively charged nucleus that was orbited by _____________.
What are electrons?
100
The number that represents atomic weight
What is 4.003?
100
Negatively charged particles found outside the nucleus of an atom
What are electrons?
100
These are constantly in motion, more or less based on their state
What are atoms?
100
The "stuff" all objects and substances in the universe are made of
What is matter?
200
The 1898 model of the atom proposed by J.J. Thomason was called the plum pudding model because he thought the electrons were spread out ____________ throughout the positively charged material of the atom.
What is evenly?
200
The atomic number
What is 14?
200
The electrically neutral part of an atom
What are neutrons?
200
This determines the speed of which atoms move
What is heat?
200
The amount of matter in an object, similar to weight
What is mass?
300
This Greek philosopher proposed the existence of atoms in 440 B.C.
Who is Democritus?
300
Russian chemist who organized the periodic table of elements
Who is Dimitri Mendeleev?
300
The positively charged particle found in an atom
What are protons?
300
The different levels at which electrons move around a nucleus
What are shells or energy levels?
300
The amount of space a thing fills
What is volume?
400
John Dalton's early 1880s model of the atom proposed that atoms were small, dense, ________ spheres that could not be created, altered, or destroyed.
What is hard?
400
The method in which the elements are organized on the periodic table
What is their properties?
400
These stick together to form the nucleus of an atom
What are protons and neutrons?
400
The name of two or more atoms joined together
What are molecules or compounds?
400
How much matter is packed into the space an object fills
What is density?
500
In 1913, Niels Bohr changed the model proposed by Rutherford to note that electrons traveled in circular orbits around the nucleus at certain ________ _________.
What are energy levels?
500
The chemical symbol
What is B?
500
Atoms of the same element that have different numbers of neutrons
What are isotopes?
500
Two types of changes matter can go through
What is chemical and physical?
500
The absence of matter
What is a vacuum?