Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
33 Cards in this Set
- Front
- Back
|
What is an element?
|
substances that are so simple they cannot be broken don by ordinary chemical reactions into anything simpler (9 2 elements, 11 gasses + 2 liquids); Consist of metals/nonmetals/noble gasses
|
|
|
What are atoms?
|
the smallest particle of an element still having the properties of the element
|
|
|
What are compounds
|
two or more elements chemically combined. Have fixed or definite proportions (law of definite proportions). Compounds are composed of molecules.
|
|
|
What are molecules
|
The smallest quantities into which a compound can be divided without the loss of its characteristics.
|
|
|
What is the most common element in the earth's crust? In living things?
|
O2
|
|
|
What elements possess unique fitness for biological materials
|
O,C,H,N,P and S: all nonmetals (form covalent bonds -> stable molecules). Carbon forms the most covalent bonds.
|
|
|
What does the atomic number represents
|
The number of protons in an atom
|
|
|
What two forces hold the electrons in the atom?
|
1) gravity (pull of masses toward each other) and 2) electrical attraction between the protons and electrons
|
|
|
What determines the chemical activity of an atom
|
Its electron configuration (specifically, valence)
|
|
|
Why do isotopes of the same element behave the same
|
Because they have the same electron configurations (b/c they have the same # of protons)
|
|
|
What is the mass of an electron
|
1/8000 AMU (insignificant)
|
|
|
Which isotopes are more radioactive?
|
Ones with higher mass numbers (more neutrons -> less stable -> radioactive decay)
|
|
|
What is the most common isotope of carbon?
|
C-12
|
|
|
What are AMUs measured in propotion to?
|
C-12 is set with a weight of 12, and AMUs are measured in relaitonship to it (i.e. 1 AMU = 1/12 the weight of C-12)
|
|
|
How does the distance of the shell from the nucleus relate to the number of subshells?
|
shells farther from the nucleus have more subshells
|
|
|
What is the valence shell?
|
The outermost shell of an atom ith the most energetic electrons that participate in bonding. Atoms achieve stability by filling their valence shell
|
|
|
Describe the first shell
|
1s. Holds 2 electrons
|
|
|
Describe the second shell
|
2s,2px,2py,2pz. Holds eight electrons.
|
|
|
Describe the third shell
|
s,p,d. Holds 18 electrons
|
|
|
Describe the fourth shell
|
s,p,d,f. Holds 32 electrons.
|
|
|
What is the pauli exclusion principle?
|
Only two electrons can occupy any given orbital, and the electrons must have opposite spins.
|
|
|
What does the roman numeral over the "family" (column) in the periodic table represent?
|
The number of valence electrons.
|
|
|
What is ionization potential?
|
How must energy is required to bring about removal of an electron from one of its atoms. (Increases Left->Right. Flourine is most electronegative). Noble gasses have the highest ionization potentials (w/ He the highest)
|
|
|
What are metals?
|
Atoms that form chemical bonds by losing valence electrons. They have a mostly-empty valence shell. They only react chemically w/ nonmetals, and when they do they form cations (e.g. Na+).
|
|
|
What are nonmetals?
|
They form chemical bonds by accepting or sharing valence electrons. They react with both metal (ionic) and nonmetals (covalent - sharing electrons). Their valence shell is half-or-more full.
|
|
|
What is an ion?
|
An atom that has lost or gained one or more electron.
|
|
|
What is an anion? A cation?
|
A cation has a positive charge (metals). An anion has a negative charge (nonmetals).
|
|
|
What are radicals?
|
Polyatomic ions (like PO4-3)
|
|
|
What is electronegativity?
|
The ability of an atom or group of atoms to attract a shared pair of electrons (F is most electronegative)
|
|
|
What is oxidation number/state?
|
The number and sign of the electric charge that the ion of an element has - indicates the number of electrons that must be lost (positive oxidation #) or gained in bonding to become stable.
|
|
|
In ionic compounds, what is the sum of the oxidation numbers?
|
0
|
|
|
What is valence/electrovalence?
|
The number of ionic bonds the atom can form. Same # as oxidation #, but no sign.
|
|
|
What is covalence?
|
The number of covalent bonds the atom can form (# of non-paired electrons in valence shell). H=1, O=2, N=3 or 4, C=4
|
