What is matter?
Anything that takes up space and has mass. Ex: Air; something that isn't matter: light (think of the filling up a balloon metaphor)
What is an element?
A substance that cannot be broken down to other substances by chemical reactions.
What is a compound?
a substance consisting of two or more different elements combined in a fixed ratio.
Difference between an element and a compound?
A compound has characteristics different from those of its elements. Table salt, for example, is sodium chloride (NaCl), a compound composed of the elements sodium (Na) and chlorine (Cl) in a 1:1 ratio. Pure sodium is a metal, and pure chlorine is a poisonous gas. When chemically combined, however, sodium and chlorine form an edible compound.
Define Subatomic particles, their charges, where they're found, and their relative mass.
Protons - positive; in nucleus; 1 dalton (or amu)
Neutrons - neutral; in nucleus; 1 dalton (or amu)
Electrons - negative; found outside nucleus; 0 nothing
What are isotopes?
Different forms of the same element; they differ in number of neutrons, but they have the same # of protons and behave identically in chemical reactions
How many electrons does it take to fill the first orbital shell? The second? The third?
First shell - 2
Second shell - 8
Third shell - 8
Difference between compound and molecule?
Compound is a mixture of at least two different elements, while a molecule is a 2 or more atoms of a single element.
What are covalent bonds? Single? Double?
Two or more atoms SHARING ELECTRONS.
Single covalent bonds - sharing of one pair of valence electrons
Double - sharing of two pairs of valence electrons
What are polar covalent bonds?
The sharing of electrons UNEQUALLY; atoms have differing electronegativities
What are non-polar covalent bonds?
The sharing of electrons EQUALLY; atoms have similar electronegativities
What is electronegativity?
One atom's attraction of the electrons within one covalently bonded molecule
O > N > C > H
Oxygen - most electronegative element
Difference between covalent and ionic bonds?
Covalent bonds are the SHARING of electrons, whether it be equally or unequally
Ionic bonds are the GAINING or LOSING of electrons, NOT SHARING
What is a hydrogen bond? Strong or weak?
Partial plus of a Hydrogen in a polar molecule forms a bond with a Partial Minus of another polar molecule; Weak bond.
What are trace elements?
Elements required by organisms in minute quantities; ex: humans need iodine in small quantities or we'll get goiter
Define the potential energy level of electrons and the Kinetic energy level.
Potential energy - stored energy due to location or structure; ready to use energy
Kinetic energy - energy in motion or movement; currently using
Choose 2 elements essential to life, draw the electron configuration of each as an ion and note the charge of the ion.
Ex: O - only 6 rings on outer shell, so it wants to gain 2, making it 2- charge
What is a chemical reaction? Be able to identify the products and reactants in a chemical reaction.
The making and breaking of chemical bonds.
1. Reactants - structure of chemicals prior to a chemical reaction
3. Products - structure of chemicals as a result of a chemical reaction
What bond does a SINGLE molecule of water have? (H₂O)
Polar covalent bond.
(it's when there's more than one polar molecule that hydrogen bonding takes place)
What bond do two oxygen's share?
Non-polar covalent bond; they have equal electronegativity so they share their e⁻