Exam 2 Study Guide
1) How many elements are there?
2) How many of those elements are naturally occurring? 88
3) What is the chemical symbol?
A representation of an element
4) What is the chemical symbol for potassium? K
5) What is the chemical symbol for cobalt?
6) Are groups vertical or horizontal?
7) What are the groups?
8) What are the rows that are counted from top to bottom? Periods
9) How many periods are on the periodic table? 7
10) Alkali metals are in what group?
11) What are the properties of Alkali metals? Soft, shiny, very reactive
12) Alkaline earth metals are in what group?
13) What are the properties of Alkaline earth metals? Shiny, not as reactive
14) Halogens are in what group?
15)What are the properties of halogens?
16) Noble gases are in what group?
17)What are the properties of noble gases?
18) What does the black zigzag represent?
The separation between metals and nonmetals
19)What are the properties of metals?
shiny and ductile, and conduct heat and electricity. Are solid except for mercury 20) What are the properties of nonmetals?
Dull, brittle and poor. Have low densities and meting points Don't forget about the age old question of endomysium covers
21) What are all elements made out of?
22) What are atoms composed of?
Proton, neutrons, and electrons
23) What does AMU stand for?
Atomic mass unit
24) What subatomic particles have the same AMU?
Protons and neutrons
25) In an atom, where are the protons and neutrons located?
26) How do you find the number of protons and electrons?
27) What is the mass number equal to? If you want to learn more check out words ending in uf
Protons + Neutrons
28) What are isotopes?
atoms of the same element that have the same atomic number but different numbers of neutrons. Equal number of protons but different numbers of neutrons. 29) When writing a symbol, is the mass number on top or bottom? Top If you want to learn more check out jeffrey schulze utd
30) What is the atomic mass?
the weighted average of the mass of all the naturally occurring isotopes of that element.
31) What are the regions occupied by electrons called?
Principal energy levels or shells
32) What letter represents the number of shells?
33) What does N stand for?
34) What is the formula given to find the maximum number of shells? 2n ❑2
35) What letter represents the first energy level?
36) What letter represents the second energy level? Don't forget about the age old question of if a company determines cost of goods sold each time a sale occurs, it
37) What letter represents the third energy level?
38) What letter represents the fourth energy level?
39) What letters are subshells identified with?
40) How many orbitals does P subshell have?
41) How many orbitals does D subshell have?
42) How many orbitals does F subshell have?
43) How many electrons can each orbital hold?
44) Do electrons in each orbital attract or repel?
45) If an orbital is closer to the nucleus does it have more or less energy? Less
46) Are orbitals filled in terms of increasing or decreasing energy? Increasing
47) What is hydrogens' electron configuration? If you want to learn more check out study en progresivo
48)What is the Heliums electron configuration?
49) What is Lithiums electron configuration?
1S ❑2 2S ❑1
50) What is Carbon's electron configuration?
1s ❑2 2s ❑2 2p ❑2 We also discuss several other topics like developmental schism
51) What are electrons in the valence shell called?
52) What is the outermost shell called?
53) The chemical properties depend on what?
The number of electrons is the valence shell
54) The number of valence electrons is equal to what?
Lettered group number
55) What is the distance from the nucleus to the outer shell? Atomic size
56) The atomic size increases going from what?
Top to bottom
57) The atomic size decreases going from what?
Left to right
58) What is the energy needed to remove one electron from an atom in the gaseous state?
59) Ionization energy decreases going?
Down a group
60) Ionization energy increases going?
Left to right
61) What are the four types of radiation?
alpha, beta, positron, and a gammaray
62) What is an alpha particle?
High energy particle containing two protons and two neutrons
63)What is a beta particle?
High energy electron. The electron needed to convert one neutron to a proton 64)What is a positron?
(the antiparticle of a B particle) � +¿∨❑+1
❑¿. The positive electron needed to
convert a proton to a neutron
65) What is a gammaray?
High energy radiation released from a radioactive nucleus. They are a form of energy, so they have no mass and no charge.
66) What are the components of a nuclear equation?
original nucleus → radiation + new nucleus
67) What is alpha decay?
Emitting of two particles
68) What is beta decay?
The decay of a nucleus by emitting a Particle. The atomic number increased by � 1, the mass number remained the same
69) What is positive emission?
the decay of a nucleus by emitting a position � +¿❑¿
The mass number of the new nucleus is the same but the atomic number decreases by 1
70) What is the halflife of a radioisotope?
Time for the value to decrease by 50%
71) What is the instrument used to detect radiation?
72) What is the unit for radiation?
73) What is nuclear fission?
The large nucleus breaks into smaller nuclei
74) What is nuclear fusion?
Combines smaller nuclei into a larger nucleus
75) Are large amounts of energy released in both?
76) Are high temperatures required for fusion or fission?
77) What is the octet rule?
8 valence electrons
78) When does an ionic bond occur?
when valence electrons of a metal atom are transferred to the atom of a nonmetal
79) What is an atom or molecule with a net charge due to the loss or gain of one or more electrons?
80) What are positively charged ions called?
81) Do cations lose or gain electrons?
82) What are negative charge ions called?
83) Do anions lose or gain electrons?
84) What is the symbol for the ion that has 7 protons and 10 electrons? N 3−¿
85) What is it when one or more electrons are transferred from a metal to a nonmetal which forms positive and negative ions?
86) What should the overall charge be for ionic compounds?
87) What two elements are ionic compounds made of?
Metals and nonmetals
88) Is a cation a metal or nonmetal?
89) Is an anion a metal or nonmetal?
90) What is a group of covalently bonded atoms with an overall ionic charge? Polyatomic Ions
91) What consists of atoms of two or more nonmetals that share one or more valence electrons?
92)What results from the sharing of electrons between two atoms? Covalent bonds
93)Molecular compound name of NO ❑2 ?
94) What is a molecular formula that shows the number and identity of all the atoms in a compound, but not which atoms are bonded to each other?
95) What does the Lewis Symbol represent?
the valence electrons as dots placed on sides of the symbol for an element 96) Does the central atom in Lewis Structure have the most or least number of atoms?
97) When Drawing lewis structure for polyatomic ions, what two things are different? The atoms and electrons are placed in brackets, and the charge is written on the outside upper right.
98) Are the bonding electrons shared equally in HH?
99) Are the bonding electrons shared unequally in HCl?
100) Is there an equal sharing of electrons in a nonpolar or polar bond? Nonpolar
101) What is the ability to attract the shared electrons in a chemical bond? Electronegativity of an atom
102) What value is an atom assigned regarding the amount of electronegativity?
0 to 4
103) What symbol indicates electrons being pulled toward each other? S
104) What is a dipole?
A polar covalent bond that has separation of charges
105) What kind of bond is an equal sharing of electrons?
106) What kind of bond is an unequal sharing of electrons?
107) What kind of bond is a result of an electron transfer?
108) What is the molecular shape of twoelectron groups?
109) What is the molecular shape of threeelectron groups?
110) What is the molecular shape of fourelectron groups?
1. Elements and Symbols
Elements are the primary substances of matter
Chemical symbols are one or twoletter abbreviations of the names of the elements
2. The Periodic Table
Arrangement of the elements by increasing atomic numbers.
A horizontal row is called a period
A verticle column is a group
Group 1A is Alkali; Group 2A are alkaline earth metals; group 7A are halogens; group 8A are noble gases
Metals are on the left of the zigzag, nonmetals are on the right
elements along the zigzag are called metalloids
3. The Atom
Smallest particle that retains the characteristics of an element
Atoms are composed of three types of subatomic particles
Protons and Neutrons are in the nucleus, electrons are on the outside 4. Atomic Number and Mass Number
The atomic number gives the number of protons and electrons
The mass number is the total number of protons and neutrons in an atom 5. Isotopes and Atomic Mass
Atoms that have the same number of protons but different number of neutrons are isotopes
The atomic mass is the weighted average mass of all the isotopes in a naturally occurring sample of that element
6. Electron Energy Levels
An orbital is a region around the nucleus where electrons are found
Each orbital holds a maximum of two electrons
In each energy level (n), electrons occupy orbitals of identical energy within sublevels
An s sublevel contains 1 S orbital, 3 P orbitals, 5 D orbitals, 7 F orbitals 7. Electron Configuration
Within a sublevel, electrons enter orbitals in the same energy level one at a time until all orbitals are halffilled.
The orbital diagram shows the orbitals that are occupied by paired and unpaired electrons
The electron configuration for silicon shows the number of electrons in each sublevel: 1s22s❑22p❑63s❑23p❑2
An abbreviated electron configuration for silicon places the symbol of noble gas in brackets to represent the filled sublevels: [Ne] 3s23p2
The periodic table consists of s,p,d, and f sublevel blocks
8. Trends in Periodic Properties
The properties of elements are related to the valence electrons of the atom Each group has the same arrangement of valence electrons but different energy levels.
The Lewis symbol of an atom shows the valence electrons, represented as dots, around an element symbol
The size of an atom increases going down down a group and decreases going from left to right across a period
The metallic character of an element increases going down a group and decreases going from left to right across a period