Chemistry Flashcards
What is matter?
Any substance that has mass and takes up space
What are atoms?
the smallest complete unit of matter
What is a molecule?
a bonded combination of at least two atoms
What are the three components of an atom?
Protons, neutrons, and electrons
What is the principle of Conservation of Mass?
The amount of a substance at the start of a reaction = the amount of that substance after the reaction.
What are the three primary states of matter?
Solid, liquid, gas
Describe a solid
Fixed volume and shape, atoms extremely close together, lowest atom movement
Describe a liquid
Fixed volume, shape changes to fit container, atoms have more movement and space than solid
Describe a gas
No fixed volume or shape, expands to fill whatever container it’s in, atoms have the most movement and space between them out of all states of matter
What are the fourth and fifth states of matter?
Plasma (ionized gas) and non-Newtonian fluid (liquid that becomes solid under impact)
Who created the Periodic Table?
Dmitri Ivanovich Mendeleev
What is the one or two-letter abbreviation of an element’s name called?
its chemical symbol
What do we call the number that indicates the number protons (and electrons)?
The atomic number
What do we call the average weight of an element’s atoms?
The atomic mass
What is the outer layer of electrons called: the ________ electrons
valence
Where in an atom does all atomic bonding take place?
in the valence shell
What are the two primary types of atomic bond that form molecules?
covalent and ionic bonds
What are the two types of covalent bonds?
polar and nonpolar
What is the octet rule?
Most atoms are most stable with 8 electrons in their valence shell.
What is a covalent bond?
When atoms share a pair of electrons
What is an ionic bond?
When one atom donates an electron to another atom to complete its valence shell; the “giver” atom becomes positive, the “receiver” becomes negative, and the two atoms bond together.
What are Lewis Dot Structures?
A simple visual representation of how atoms are bonded together into molecules
What is the difference between an acid and a base?
An acid likes to donate protons, a base likes to absorb protons
Would a solution with a pH level of 1 be a strong acid or a strong base?
a strong acid
Would a solution with a pH level of 7 be a strong acid or a strong base?
Neither. 7 is neutral on the pH scale (like water)
Would a solution with a pH level of 14 be a strong acid or a strong base?
a strong base
What quality of a solution does the pH scale measure?
the amount of hydrogen ions (H+) in the solution.
What’s the relationship between the amount of protons (H+) in a solution and its number on the pH scale?
It’s inverted; High amounts = low pH (acid), Low amounts=high pH (base)
What is a solvent?
it is the liquid ingredient in a solution
What is a solute?
it is the substance added to the solution
What is Avogadro’s Number (the mole)?
6.022 x 10 to the 23rd power
How do you calculate molar mass of an atom?
Find the atom’s atomic mass on the periodic table. The molar mass = the atomic mass, written in grams/mole
What’s the first step in balancing a chemical equation?
Figure out how many atoms of each element you have on both sides of the equation
