Elements
Is an element pure or not?
YES!
3 categories of elements
Metals, nonmetals, metaloids
What is a compound?
A compound is a pure substance composed of two or more elements that are chemically combined
What is the concentration of a solution that has 35 g of salt dissolved in 175 mL of water?
0.2
A substance is _________ when it can dissolve in water.
Soluble
An example of an element in gas form
Oxygen
Nitrogen
Helium
Nitrogen
Give at least 2 characteristics of metals
Shiny
Conduct heat energy and electric current
What is a mixture?
A combination of two or more substances that are not chemically combined
What is the concentration of a solution that has 95 g of salt dissolved in 306 mL of water?
.31
Most solids are more soluble in liquids at HIGHER or LOWER temperatures?
Higher
True or False
Elements cannot be separated into simpler substances by physical or chemical means
TRUE
Give at least two examples of nonmetals
Look dull, do not conduct heat or electric current
What is a solution?
A solution is a homogeneous mixture. This means that a solution appears to be a single substance.
Particles of the substances in a solution are evenly spread out - known as dissolving
What is the concentration of a solution that has 54 g of salt dissolved in 360 mL of water?
1.5
What is a suspension?
A mixture in which the particles of a material are large enough to settle out
Each element contains only one type of particle called:
How do metalloids compare to metals and nonmetals?
Have properties of both metals and nonmetals
Solutions are often described as being concentrated or dilute. What does this mean?
Dilute - has a small amount of solute dissolved in the solvent.
Concentrated - has more solute in solution.
What is the concentration of a solution that has 18 g of salt dissolved in 106 mL of water?
0.17
What is a colloid?
(Think snow globe!)
A mixture in which the particles of a material are large enough to settle out
Each element can be identified by its unique set of properties
Each element has its own characteristic properties
Some PHYSICAL properties include:
Boiling point
Melting point
Density
Give an example of a metal, nonmetal, and metalloid
Metal: Copper, lead, tin, aluminum
Nonmetal: Iodine, sulfur, neon
Metalloid: Silicon, boron
These can be separated easily:
Mixtures
What is the concentration of a solution that has 71 g of salt dissolved in 207 mL of water?
0.34
Suspensions and colloids are the same or opposites of each other?
Opposites