Elements
What is the smallest particle of an element that retains its properties?
What is an atom?
What is a compound?
A substance made of two or more elements chemically combined.
What is a mixture?
Two or more substances physically combined.
Which method separates sand from water?
Filtration
Classify this: salt + water.
Mixture (solution)
Which element is represented by the symbol “Na”?
what is Sodium?
What are the elements in water (H₂O)?
Hydrogen and Oxygen
Salt water is an example of what type of mixture?
Solution
What method is used to separate a dissolved solid from a liquid?
Evaporation
Classify this: carbon dioxide.
Compound
What do we call a substance made of only one type of atom?
what is an element?
Give the chemical formula for carbon dioxide.
CO₂
Sand and iron filings is an example of which type of mixture?
Suspension
What process separates a liquid mixture based on boiling points?
Distillation
Which separation technique is used in the production of drinking water?
Filtration and distillation
Which element makes up most of the air we breathe?
what is nitrogen?
Why can’t compounds be separated by physical means?
Because the elements are chemically bonded.
Is air a compound or mixture?
Mixture — it contains several gases not chemically combined.
Which technique is used to separate dyes in ink?
Chromatography
Identify: iron + sulfur heated together → iron sulfide. What is this?
A compound
Name one element we use at home on a daily basis
what is Chlorine?
Give the chemical formula for table salt.
NaCl
How do mixtures differ from compounds?
Mixtures can be separated physically; compounds cannot.
Why can a magnet separate iron from sulfur but not salt from water?
Iron and sulfur are physically different; salt dissolves in water.
What is the main difference between elements, compounds, and mixtures?
Elements—1 type of atom; Compounds—chemically combined; Mixtures—physically combined.