Ch. 2 - Nature of Molecules Flashcards
What is matter?
Anything that has mass and occupies space
What is a substance that cannot be broken down?
Element
What are the three components that make up an atom?
Protons, Neutrons, and Electrons
What does the atomic number of an element represent?
The number of protons
How do you calculate the atomic mass of an element?
Take the sum of the # of protons and the # of neutrons
What are atoms of the same elements called when they have a different amount of neutrons?
Isotopes
What are radioactive isotopes most commonly used for?
Tracking molecules in chemical reactions
What is half-life?
The amount of time it takes for one-half of the atoms in a sample to decay
What are the most common elements that the human body is composed of?
Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorous, and Sulfur
The rows on the periodic table are called what?
Periods
The columns on the periodic table are called what?
Groups
What are the outer-most electrons called on the Bohr Model?
Valance electrons
How many valance electrons are nonreactive elements going to have?
Eight
What is the Octet rule?
Atoms are going to be the most stable when they have eight electrons in their valance shell