Chemistry Flashcards
What is matter?
Any substance that has mass and takes up space
What are atoms?
the smallest complete unit of matter
What is a molecule?
a bonded combination of at least two atoms
What are the three components of an atom?
Protons, neutrons, and electrons
Who was the first to propose Atomic Theory?
John Dalton - 1803
What are the two properties that we use to categorize elements?
physical and chemical properties
Name an example of a elemental physical property.
Options: Color, size, density, malleability, magnetism, solubility
What is a chemical property?
When the inherent structure of an element changes (seen in physical properties!)
What is the principle of Conservation of Mass?
The amount of a substance at the start of a reaction = the amount of that substance after the reaction.
What are the three primary states of matter?
Solid, liquid, gas
Who created the Periodic Table?
Dmitri Ivanovich Mendeleev
What is the one or two-letter abbreviation of an element’s name called?
its chemical symbol
What do we call the number that indicates the number protons (and electrons)?
The atomic number
What do we call the average weight of an element’s atoms?
The atomic mass
What is the outer layer of electrons called: the ________ electrons
valence