Matter and Mixtures
This WHMIS symbol depicts a liquid dripping onto a hand and a piece of metal, indicating its risk of damage to the body and metal surfaces.
What is corrosive?
Dissolving chlorine or NaCl in water is an example of this type of change.
What is a physical change?
A pure substance made up of two or more elements chemically combined together.
What is a compound?
The element symbol for lead.
What is Pb?
The name for vertical columns on the periodic table.
What are groups?
A mixture in which particles are uniformly scattered.
What is homogenous mixture?
The only way you can be sure that a chemical change has taken place.
What is a new substance has been formed?
The scientist that first called indivisible particles "atoms" and identified that atoms of an element are identical in mass and size.
Who is John Dalton?
The type of element found along the staircase on the periodic table.
What are metalloids?
Who is Dmitri Mendeleev?
A heterogenous mixture made of large particles that are uniformly mixed but will settle if left undisturbed.
What is a suspension?
Combustibility, toxicity, and stability are examples of this.
What is a chemical property?
The positively charged subatomic particle that determines the identity of an atom.
What is a proton?
A family of metals that is very reactive due to their single valence electron.
What are alkali metals?
As you move along the periodic table from left to right, these two quantities increase.
What are atomic number and atomic mass?
A type of colloid; examples include mayonnaise, milk, and salad dressing.
What is an emulsion?
The two types of physical properties.
What is qualitative and quantitative?
The electron(s) that exist in the outermost shell/orbital of an atom.
Argon, a member of this family, is used in welding to prevent oxidation due to its nonreactive properties.
What are noble gases?
Around 1915, discoveries in atomic structure led scientists to organize the periodic table by this value, rather than just atomic mass as Mendeleev had done.
What is atomic number?
Examples of this type of mixture include metal alloys such as steel, bronze, and brass.
What is a solution?
The property of a substance that allows it to be stretched into thin wires.
What is ductility?
The name for elements that have varying numbers of neutrons in their nucleus.
What is an isotope?
The average number of neutrons in a magnesium atom.
What is 12?
The number of shells occupied by the electrons of a given element correspond with this value on the periodic table.
What are periods?