Classification of Matter Flashcards
What is a substance?
Matter with a definite chemical composition
What are two types of substances?
Elements and Compounds
What is a mixture?
Matter with a variable chemical composition
What are two types of mixtures?
Heterogeneous and Homogeneous
Are particles in a substance identical or different?
The particles (atoms or molecules) are identical.
Are particles in a mixture identical or different?
The particles are different. They can be different atoms, different molecules, or both atoms and molecules.
What is an element?
Matter that cannot be broken down into a more simple substance by ordinary chemical or physical methods.
When carbon 14 undergoes radioactive decay and forms nitrogen and a beta particle, does this event contradict the definition of an element?
No. Nuclear changes are not ordinary chemical or physical methods.
Sodium contains protons, neutrons, and electrons. Does this observation violate the definition of an element?
No. Subatomic particles are identical for any substance. One element is different than another.
What is the smallest particle of an element that has all the properties of that element?
An atom
What is a chemical symbol?
A shorthand method to identify an element.
Could “ca” be a chemical symbol for calcium? Why or why not?
No. It does not begin with a capital letter.
Could “CA be a chemical symbol for calcium? Why or why not?
No. The second letter must be lower case. Two capital letters could possibly be a chemical formula for a compound.
What is the definition of a compound?
Matter composed of two or more elements bonded together in a specific ratio.
Are two oxygen atoms bonded together a compound? Why or why not?
No. Compounds are made from two or more different elements.
What is a chemical bond?
A force that holds atoms together in a molecule.
Hydrogen peroxide and water are made from the same elements, hydrogen and oxygen. Hydrogen peroxide has a 2:2 ratio, while water has a 2:1 ratio. Are they the same substance?
No. Compounds made from the same elements with different ratios are different compounds.
What is the smallest particle of a compound that has the properties of that compound?
A molecule
A compound is made from carbon and oxygen. It is broken down into oxygen and carbon . Are carbon and oxygen the same as a compound made from carbon and oxygen?
No. Compounds are different substances from the elements that made them.
What must happen for a compound like water to be broken down into hydrogen and oxygen?
A chemical change must occur.
What is a chemical formula?
A shorthand method to identify which elements are in a compound and how many atoms of each are bonded together.
What is a heterogeneous mixture?
A combination of substances that are distinguishable.
The shorthand representation for nobelium is “No.” Is this an element or a compound?
“No” is an element because the second letter is small case.
What is the name of the chart containing all the known elements on Earth?
The Periodic Table of the Elements
The shorthand representation for nitric oxide is “NO.” Is nitric oxide an element or a compound?
“NO” is a compound because both letters are capitalized.
A student mixes sand and iron filings together to make a mixture? Is this a heterogeneous or homogeneous mixture?
Heterogeneous because the student can see the sand particles and the iron particles.
Filtration uses what property of matter to separate a mixture of sand and gravel?
Size
Iron is attracted to a magnet. In a mixture of iron and sand, why can a magnet be used to separate the iron?
The substances in a mixture retain their properties.
Why do substances in a mixture retain their properties?
No chemical bonds are broken or made when the substances combine.
What is a colloid?
A mixture in two states of matter where at least some of the particles are intermediate in size.
Why would blood be considered a heterogeneous mixture?
Under magnification, the different types of cells and the plasma can be distinguished.
What is a suspension?
A mixture in two states of matter where at least some of the particles are visible without magnification.
Muddy water and salad dressing would be examples of a colloid or a suspension?
A suspension
What is the difference between a homogeneous and a heterogeneous mixture?
The parts of a heterogeneous mixture can be distinguished. The parts of a homogeneous mixture are so small that they cannot be distinguished, even with magnification.
What is a subscript?
The small number that follows a chemical symbol and that indicates how many atoms of that element are in the compound.
Which subscript number do chemists not write?
one
What is a solution?
A homogeneous mixture that is uniform throughout.
What is the solute?
The substance being dissolved.
How does the state of matter of the solute and solution compare?
The solute can be the same state of matter or a different state than the solution.
What is the solvent?
The substance that does the dissolving.
How does the state of matter of the solvent and solution compare?
The solvent and the solution are usually in the same state of matter.
What is solvation?
Process where the solvent surrounds the solute and pulls it into solution.
What is dissociation?
Process where the solvent pulls apart an ionic solute into ions before surrounding the ions in solution. Enables the solution to conduct electricity.
What is an electrolyte?
A substance that when it is put into solution, allows the solution to conduct electricity.
What is an unsaturated solution?
A solution that can hold more solute at that temperature.
If a test amount of solute is added to an unsaturated solution, what will happen?
The test amount of solute will dissolve.
What is a saturated solution?
A solution that is holding as much solute as possible at that temperature?
What happens when a test amount of solute is added to a saturated solution?
The test amount of solute will settle to the bottom of the container.
What is a supersaturated solution?
A solution that is holding more solute than it should at that temperature?
What happens when a test amount of solute is added to a supersaturated solution?
The solution will precipitate solute until it becomes a saturated solution.
How can the amount of a solid solute that a solution can hold be increased?
For most solid solutes, increasing the temperature will increase the amount that can be dissolved.
