Matter Flashcards
What is Matter?
o Takes up space - (i.e., it has volume)
o Has mass
o Is made up of atoms - the smallest particles of matter
o Energy is not made of matter, but everything else is
What are atoms?
o The smallest particles of matter
o Made up of subatomic particles
o Has a nucleus, containing protons, and neutrons
o Has electrons in orbit around the nucleus
What is a molecule?
Two or more atoms chemically bonded (Unstable atoms can be attracted to other unstable atoms) together is called a molecule
What are elements?
o Elements are made up of one type of atom - (i.e. all their atoms are the same)
o Elements cannot be broken down into anything simpler
o There are 118 elements (94 occur naturally, others are man-made)
o Elements are found on the periodic table
o Each element has a unique chemical symbol
o Elements can be made of molecules
What is a compound?
o A compound is made up of more than one element chemically bonded together
o Compounds can be described by a chemical formula - this states which atoms are in one unit of the compound (e.g. NaCl)
o Not all compounds are made up of molecules, but many are (e.g., H2O)
What is an impure substance?
An impure substance has a non-constant chemical composition (the substance is made of different stuff throughout
How can I classify substances?
• Elements are always on the periodic table
o Names are on word and often end in ‘ium’
• Compounds often have two-word names
o E.g., sodium chloride, hydrogen sulphide, etc
• Not all compounds go by a two-word name
o E.g., water, ammonia, methane, etc
• Mixtures have multiple ingredients
What is Homogeneous?
• Homogeneous - Homos = same; Genos = kind
Something is homogeneous if its constituents (i.e. what the mixture is made of) are distributed uniformly throughout the mixture
What is a pure substance
a. A pure substance has a constant chemical composition (the substance is made of the same stuff throughout)
b. Pure substances can be described with a chemical formula
c. Elements and compounds are both pure substances
d. Pure substances have constant chemical and physical properties (e.g. melting point, boiling point, density)
What is heterogeneous?
• Heterogeneous - Heteros = other; Genos = kind
o Something that is heterogenous does NOT have its constituents uniformly distributed
o The components are usually physically separated from other components
What is an impure substance a combination of?
Impure substances are made of a combination of two or more pure substances.
What is an impure substance a combination of?
Impure substances are made of a combination of two or more pure substances.
