Elements
What is the smallest part of an element?
Atom
What is a heterogeneous mixture?
have visibly different pieces.
What are the components of water (H₂O)?
two hydrogen atoms and one oxygen atom
What defines a pure substance?
Has the same properties because a substance has a fixed, uniform composition
Includes elements and compounds, NOT mixtures
What are the three types of homogenous mixtures?
solution, suspension, colloid
Give an example of a pure substance.
Aluminum (foil), Helium (balloons), Table salt (NaCl), Carbon dioxide
Can you give an example of a homogeneous mixture?
Ex: pool water, milk, blood
What is table salt's chemical formula?
NaCl
How do compounds differ from mixtures?
compounds are pure and mixtures are impure
Turn this number into scientific notation
230000
2.3x10^5
What is a compound?
atoms stuck together to form new units of matter
What happens to a suspension over time?
separates over time
How is a compound formed?
atoms stuck together to form new units of matter
What is an example of a fixed composition?
pure substances have a fixed composition so any element or compound
Turn this number into normal notation
4.5x10^-6
0.0000045
How many types of atoms are in a compound?
two or more
What is a solution & give an example
something dissolved OR combination of matter in the same phase
alloys- mixtures of metals
air- mixture of gasses
What is the difference between elements and compounds?
Element- all one type of atom, can be seen on the macroscopic level
Compounds- atoms stuck together to form new units of matter
Explain the term "uniform composition."
substance where the composition is the same throughout
Convert the following:
67kg = _________ g
67000g
Define an element.
all one type of atom, can be seen on the macroscopic level
What is a colloid & give an example
has intermediate sized particles
Name a common compound and its elements.
NaCl. one sodium atom and one chloride atom
What is the role of atoms in compounds?
atoms stick together to form compounds
What is a meniscus and why is it important?
the curve in the water in a grad cylinder. for accuracy and precision when measuring liquids